I am looking for the shortest comprehensive way to explain to people that are trying to use DRM as a technology to prevent users from using their data in some fashion deemed undesirable, why their solution cannot work by definition.
"Okay, let me have a stab at combining (albeit inelegantly) the best points from the other answers... I'll make this answer CW so that if someone sees a chance to improve the polish (or content) they can (plus I don't want to gain rep for combining other people's answers).
With DRM, you're giving people the means to unlock the content you've protected, along with the content itself. Someone's going to find that ""key"" at some point, thus defeating it. At some point, you have to decrypt the content. If the hacker(s) can get access to this data then they've defeated your DRM. At some point, you also have to show the content to the user and then he/she can simply re-record it ""in the clear"" from that data. See Analog Hole (This is less of a problem with games, as interactive content can't easily be recorded then interacted with again at a later date) DRM only punishes legitimate buyers, because adding DRM is only going to reduce the scope in which they can use your work and thus makes them less inclined to buy it. All it takes is one person with the skill, tools, and time to crack it then it can be shared with anyone and there's no point in buying your version (except if you don't want to do something illegal of course! (Or if you honestly want to support the maker)). Many people will opt to use a free version of your product regardless of the legality of using it without your DRM, because you are imposing unreasonable restrictions on how, where and why they use your work. Spore is a good example of this, as are many other programs/games/etc."
"To sum the anti-DRM argument up in one easy word?
SPORE
How could a game with such intrusive DRM restrictions not be able to stop its excessive piracy rate.
If you wanted the hypothetical politician to understand why DRM wont work, don't give them a tech talk, give them a shining example of where it went wrong. One key point that 'management types' need to understand is that a pirated copy (DRM bypassed) is not equivalent to a lost sale. It just so happens that people are prepared to pay good money for products when they see the value in those products. ""Copy protection actually increases rather than decreases the piracy of games."" What left wing nut job said that?? It was only Gabe Newell from Valve. Ignorant companies are now competing with their own product, they now have to compete with 'free'.
When software is cracked (generally within the first day of release), DRM then only hurts the loyal consumers who paid for the product.
Side comment: A good quote I found on the Internet regarding gaming piracy and steam.
"This is not a technical, more a social answer, so it might not be exactly what you asked for:
Nobody who would illegaly copy a piece that's not DRMed, would even pay a penny for it if it were DRMed. They'd find a way to get it for free or not get it at all.
So, you're not winning anything (as in: cash) by DRMing; however, you're driving away the honest customers, because even if there were such a thing as a secure DRM, it could never be frictionless for the user."
"DRM solves an imaginary problem If a song or piece of software has been pirated 10,000 times, that does not equal 10,000 lost sales, for several reasons.
The demand curve. A product that sells 10,000 copies at $1 might only sell 500 copies at $10. This is basic economics. The free factor. The biggest leap on that demand curve will be between $0 and $1. If something is free, it is zero-risk. Lots of people will get it on a whim to see if they like it. Even a price of $0.01 could drop the number of downloads considerably, if it means having to negotiate a transaction. Viral impact. Although a free product may undermine some of the market for a paid version, it can also create a market. Consider Windows, which has been pirated widely in places like China, spurring on legitimate sales. What if they had just used Linux? Or consider Adobe Photoshop. It's an industry-standard piece of software that costs more than $500. Businesses will pay for it, but high school students probably can't. Which scenario is better for Adobe?
Students never get their hands on Photoshop until they get to college or the work force, at which point, having no preference, they'll use whatever software someone provides them Students pirate Photoshop and started tinkering at age 12, know it inside-out before they ever get to college, put it on their resume, and scoff at the suggestion of using anything else when they're in the work force
DRM assumes that ""piracy is always bad,"" when in fact, piracy has pros and cons. In general, though, it seems that ""everybody pirates our product"" is preferable to ""nobody has heard of our product."""
