Yeah, it happens. Remember, Facebook is sensitive to the friend request reject ratio. So even if yous end 25, but a high % ignore and report it, you will get blocked. What's the solution? Target who you friend request- esp. in the beginning. If you're using a hot chick as a profile, don't friend older, married women. In fact, just request young, single males. Try targeting your friend requests to reduce your reject ratio; then when you're stable, you can think about loosening your targeting. So far this has worked reasonably well for me.