I didn't mean to hide them, though that is similar to what I was saying. I was saying to mark as spam all users who fill in profile info during registration. The fields are there for people to fill in - however, there should be a message telling legitimate users to wait until after registration to fill in their profile.
I've seen it once before and I thought it would be reasonable spam protection. This works because literally every spam bot fills in random profile info, avatar, etc. during registration, and the spambots won't read the message telling them not to.
I don't really have PHP skills. So I'll just forget about it