So many "Add Me" pages dissapear from facebook

I just realise so many fb pages I used to use to add friends are dissapear from facebook, like mafia wars.
Anybody realise this too?
Anyway I just read some post here, about you can't add friends easily anymore
?This Friend Request Can?t Be Sent?

or
"facebook can not send friend request to this person, as you do not know him personally"

Looks like facebook really fight spammer lately

I'm noticing this as well, it's getting harder and harder these days.