I'm also on Fios, and I've never gotten dinged for downloading too much, although I'm sure I've hit it in the past. I'll have to check their site if I can stand navigating it (their customer portal is worse than most cell phone carriers').

*edit*
I'm on my Verizon Fios customer portal, and it's even worse than I can remember. If they DID have a bandwidth cap, I'm pretty sure there's be a class action lawsuit because I see absolutely no way of determining how much bandwidth I've used. Their site is an absolute mess and it's horribly slow, which is weird.

BTW, that's another thing about Google Fiber. I love the idea that I'd have far faster speeds than most web servers would be able to deliver to me. Can most CDNs even get stuff to you that fast?