Why would someone hide themselves on their facebook friends lists?

[taurusfire]

What might be the reasons that a person who had previously been visible on his facebook friends lists, is suddenly "hidden" from those lists? Previously, the person could be seen on his facebook friends lists that were set to "Public". His profile is set so that the Public cannot search for it. His profile pic previously could be seen by anyone on friends lists that are public, but now it's not showing in those lists.
Does that mean he has set his profile pic privacy setting to "Only Me"?? And if so, WHY would someone do that?

[abraXus]

if the profile isnt showing anymore, he either deactivated his account, or it was suspended by facebook

there isnt a way for him to hide himself on other peoples' friends lists

[Sumon]

For instance, you would make it impossible for a friend to see who posts and post messages themselves on your Wall. If you ... Looking for a few clues can alert you to the possibility that you've been blocked from the Wall, but not the profile or friends list of a Facebook friend. .... How to Tell Who Is Hiding You on Facebook.

[jay dee]

for me i hide it because i hate when someone starts adding people i know and out of no where they become friends.