Policy/Code that restricts usage of media that you "own".
The DRM feature is actually no use to you but people still buy it because all the companies get together and say "we will put DRM on all the products we can from now on"
A little pesky feature that only helps out the content industry but not the person owning it.
Normally you can do what you like with any product you buy, unless it has DRM in which case it will do what the content industry wants it to do as opposed to the person who owns it.
Any of the group of technologies intended to supress piracy by imposing use restrictions on all copies of a given product. The reason why most of people download their songs off eMule instead of buying the CDs. One of the most braindead ideas in the history of computing. Encourages piracy by making the pirated product more valuable than the legal one. While DRM significantly hurts the average user by restricting his/her use of the product, it is only a minor nuisance to those it is intended against (crackers, pirates etc.). Object of religious veneration among the entertainment industry despite its complete ineffectiveness.
Enhanced DRM enforcement is the core feature of Windows Vista, which makes it ca. 30% slower than XP.
(2) "A 60-year-old man with acute pancreatitis developed persistent hiccups after insertion of a nasogastric tube. Removal of the latter did not terminate the hiccups which had also been treated with different drugs, and several manoeuvres were attempted, but with no success. Digital rectal massage DRM was then performed resulting in abrupt cessation of the hiccups. Recurrence of the hiccups occurred several hours later, and again, they were terminated immediately with digital rectal massage. No other recurrences were observed. This is the second reported case associating cessation of intractable hiccups with DRM. We suggest that this manoeuvre should be considered in cases of intractable hiccups before proceeding with pharmacological agents." -- Odeh M, Bassan H, Oliven A., "Termination of intractable hiccups with digital rectal massage", Journal of Internal Medicine.