I say go for it. The more restrictions publishers put on ebooks, the easier it will be to find them free elsewhere. Same thing that happened with music.
I don't support downloading ebooks for free, but I downloaded the free music because when I bought it, I couldn't play it on all my devices.
If you won't let me check it out from the library, and continue with this price fixing that makes 10 year old books cost $8, I'm going to feel a lot less guilt downloading books as well.