I have a problem, something I'm sure a lot of video sharing companies might have. I want to start a small business by offering online video-based training courses on Microsoft Office and other office software in my town on my native language. The problem is, I'm planning to start offering cheap suscriptions for all-access to all the videos, maybe $for 5 dollars a month to get more people interested...however, I know my target audience, and I'm sure they will quickly resort to wanting to download the videos to stop paying, and who knows, maybe even share them on some site and make them public ruining my business...  My question is, is there a video format, or a way to embed, I don't know, a video file so that it cannot be downloaded for offline playback? Maybe using flash files in some remote server? I don't know...I just need a way to play videos on a web browser, that won't allow any form of downloading for offline playback and distribution. Please help guys, I'm kid of struggling to make enough money to pay for college already.  [edit] Thanks for all the information everyone...It seems there is no right answer for this, so let me rephrase the problem.   I'm going to be dealing with people with little to no knowledge of advanced computer usage. My target audience consists of 18-23 year old college students that only use their computers for Facebook, playing candy crush, watching youtube videos and doing their homework. I know most of them are now aware of how to download videos from the internet, but their knowledge is very limited (and by that, I mean sites like KEEPVID.COM or youtube-mp3.org). Most don't even know screen capture software exists, or how to get it, so I'm hoping to use that "naive" characteristic to some use.   So ok. I CAN'T stop my videos from being downloaded, but is there a way to, as I said, make it harder, say...stop sites that download the actual video file hosted/embedded? I don't mind if you can still download the video with some tricks, I just wan't my target audience to have a hard time figuring it out. Right answer goes to the most useful answer, since there is no right answer.
Is there a license / royalty free DRM available for protecting and distributing video content?
Should import statements always be at the top of a module? states:  Imports are always put at the top of the file, just after any module comments and docstrings, and before module globals and constants.  However if the class/method/function that I am importing is only used in rare cases, surely it is more efficient to do the import when it is needed? Isn't this: class SomeClass(object):      def not_often_called(self)         from datetime import datetime         self.datetime = datetime.now()  more efficient than this? from datetime import datetime  class SomeClass(object):      def not_often_called(self)         self.datetime = datetime.now() Going to Pakistan in 3 weeks time but my NICOP is expired and my son's hasn't arrived yet My NICOP is expired and I have already booked a flight to Pakistan via Qatar Airways. My wife has a valid NICOP card but my 5 years old child  has never had a NICOP or any other Pakistani ID card other than the British passport. I have made an appointment for next Monday to renew my NICOP and apply for my child's new NICOP card. My question is, what if the cards of my child and mine don't arrive in time, can we still travel to Pakistan, given that we have the receipts as a proof of application? When running umount /path I get:  umount: /path: device is busy.   The filesystem is huge, so lsof +D /path is not a realistic option.  lsof /path, lsof +f -- /path, and fuser /path all return nothing. fuser -v /path gives:                    USER        PID ACCESS COMMAND /path:            root     kernel mount /path   which is normal for all unused mounted file systems.  umount -l and umount -f is not good enough for my situation.  How do I figure out why the kernel thinks this filesystem is busy? Does anyone know the location of this login hotmail background? I want to say "someone (or something) intends to help, but instead it makes things worse". Is there any succinct expression or phrase for this?  Thanks. Does Change Data Capture (CDC) work in a SQL Server 2012 AlwaysOn Failover Cluster Instances setup? Does  work in a  setup?  There would be two nodes in the AlwaysOn Failover Cluster Instances setup and two Domain Controllers.  We are not using AlwaysOn Availability Groups.  Will CDC work? and will it failover? Why isn't the product rule used in the definition of mechanical work? How do you integrate $\int \frac{1}{a + \cos x} dx$?  Is it solvable by elementary methods?  I was trying to do it while incorrectly solving a homework problem but I couldn't find the answer.  Thanks! Given that $x^y=y^x$, what could $x$ and $y$ be? It's not too difficult to figure out that $x$ and $y$ can both be 1, and also $x$ can be 2 and $y$ can be 4 (and vice versa). But I can't rule out if there are other solutions. Does it have anything to do with inverse functions? Is there a way to see the solutions by graphing, or algebraically? If $\gcd (x,4) = 2$ and $\gcd(y,4) = 2$ then $\gcd(x+y,4) = 4$ I was working my way through some number theoretic proofs and being a newbie am stuck on this problem :     If $(x, 4) = 2$ and $(y, 4) =2$, then $(x + y, 4) = 4$,     where $(a,b)$ denotes the greatest common divisor of $a$ and $b$.   My Solution  (Incorrect)   $x-4 = 2t$ $y-4 = 2p$ $x + y - 8 = 2(t+p) \Rightarrow x + y - 4 = 2f + 4 = 2(f+2)\Rightarrow 2$ divides $(x+y , 4)$   My Question:  My solution is definitely inadequate. Can someone help me out? What exactly is a hat?  I have seen a lot of people arguing the significance of hats and the limited edition hats. I know the hats are sort of linked to the Winterbash stuff, but what exactly is a hat, what does it do, how do I get one?  Is there a full list of hats? Do fluorescent lighting and shutter speed create a problem with color cast? I took a bunch of photos at my son's martial arts club using a D90 with a 50mm F1.8.  The club is lit with overhead fluorescent lighting, and I was getting some weird results where some shots are "white", others have an "orange cast", and still others are partly white and partly orange in the same shot.  I suspect it has to do with the combination of the frequency of the light flicker and with the camera shutter speed. Here is a sequence of 3 shots that show the problem.  The shots were taken with 1/500s at F2 and ISO-800 and with Auto-WB.  First shot ("white/normal"):    Second shot ("orange cast" at top):   Third shot ("orange cast" at bottom):   These were taken in burst mode within a second of each other.  Can anybody tell me what is going on?  And, how I can avoid this? Run command whenever someone joins a Minecraft server Is there any way to run a command automatically when a player joins the server? I need to do this without the use of a Bukkit plugin. I think it's possible with MCP but I want to know how! How to block any app from being installed? My mom has an android tablet and she doesn't even know what a site is, her e-mail, or even the password of her facebook account. She's an average user. The internet is facebook in her eyes. She has no need for apps or anything, it's just, only, precisely facebook. All is facebook.  How can I completely disable installing apps in android so they can't be installed in any way or form, I mean, not by URL, not by clicking, not by app store, not even by another program. Just disable the entire thing altogether.  Doesn't need to be safe, have locks, passwords etc. I'm not trying to secure the device from intruders, attackers or robbers, I'm trying to secure it from its very own user.  Please help. I just had to remove two anti-virus apps that were opening adware pages when she tried to open facebook lite, and that's obviously a no-go, apps which she "had not installed." Clearly there's some voodoo going on here for them to just popup, or maybe she just did it unknowingly, but none of that's relevant. How can you just disable installs so this couldn't ever happen again? I'm currently typing a mathematical document which counts many sum symbols. I frequently use the align environment to render equations, although the default behaviour of this environment is to render the equations in displaystyle, which in my opinion wastes vertical space. I therefore have added \textstyle at the beginning of each line of math in this environment, but I'm looking for a more convenient solution.   So is there an environment that is similar to align with the exception it displays textstyle math by default ? Thank you. Let  $$0 \rightarrow M \rightarrow N \rightarrow P \rightarrow 0$$  be an exact sequence of $A$-modules, where $A$ is a commutative ring with unity.  Then for each natural number $i$ one can look at the induced maps  $$\mathrm{Sym}^i(N) \rightarrow \mathrm{Sym}^i(P)$$  and   $$\mathrm{Sym}^i(M) \rightarrow \mathrm{Sym}^i(N).$$  The first question is, if they are still surjective, resp. injective, i.e. is $\mathrm{Sym}^i$ an exact functor?  The second question is: what are the kernel, resp. cokernel of these maps? $N(ab) \geq N(a)$ is not necessary for the ring to be euclidean The definition of euclidean ring in my textbook is 1) $N(ab) \geq N(a)$ 2) Euclidean algorithm works. However there is a note that the first condition is not necessary. There is a hint that we can choose a following norm: $N'(a) = \min_{b\sim a} N(b)$. I do not understand why it works. We need to check that euclidean algorithm still works with this norm.   I tried to do the following. If $a \sim b$, then $a = bx, x \in K^*$. Let $N'(a)$ be $N(ax)$. Let us divide $ax$ by $bx$ instead of $b$. We get $ax = bxq + rx$, $N(rx) \leq N(bx)$. Here I am stuck and have no idea how to continue. Often I need to recall the different \tracing commands; and a couple of times I stumbled on some webpages that worked fine for me; sadly, I didn't keep them, and my searches don't take me there anymore.   So I thought I'd ask about links to where one can read a list of \tracing commands?   For instance,  mentions:  \tracingall \tracingassigns \tracingcommands \tracinggroups \tracingifs \tracinglostchars \tracingmacros \tracingnesting \tracingonline \tracingoutput \tracingpages \tracingparagraphs \tracingrestores \tracingstats \tracingscantokens   .. but, I'm pretty sure there was something like \tracingboxes (and not so sure if there was something like \tracingglues); yet I cannot find any resources mentioning those. Convert integer to hexadecimal and back again Changing Default Apache version on MacOS Sierra A DHS sweep of the network showed that one of the researchers Macs is running a non-safe version of Apache (2.4.25) and they would like him to update to at least 2.4.27.  He is having difficulty getting MacOS to use the new version of Apache rather than the one installed by default with Sierra. His issues are:  Mac OS X 10.12.6 Sierra   I have installed httpd 2.4.27 . . .  /usr/local/apache2/bin/ but the default httpd running is located at /usr/sbin/ I cannot install a new httpd into /usr/sbin/  - no write persmissions for sudo I made a root user active - but "root" does not have write permissions for /usr/sbin/ either   I cannot find any source on the web that describes how to change the httpd path from the default system version (/usr/sbin/httpd) to a new USER installed version, like /usr/local/apache2/bin/httpd  What steps am I missing?