Yeah I usually liberate my books immediately because of this reason.
DRM is a blight. People who don't want to pay for something won't suddenly go and buy the book because DRM forced them into it. That's a pretty rare case imo. So they have obtrusive, annoying and dangerous DRM on books which consumers (the people who PAY for the books) hate - just to force the additional 1% of people to buy it.
Using: Kindle DX + iPhone! EBook Fanatic!