The act of internally vandalising another persons unlogged out facebook page. This may involve changing any or all of the following: status, profile pic, relationship status, info column, comments, pages joint, etc.
Generally the greatest facebook bombing involves changes such that much of the user's friends don't realise the foul play involved.
An Atomic facebook bombing is similar but involves changing as many things as possible in the most offensive way possible.
example 1: status
Louise Genzby: Just did the biggest shit aye!! Had to chop it up with the spatula to get it to flush!!!
---Reply 1: ewwww gross!!
---Reply 2: TMI!!!
---Reply 3: hahahaa facebook bombed!!!
example 2: page joins
John Henry just joined the groups "Hot Guys", "Anal is Awesome," and "My Mother is Totally Hot"
The act of deleting all wall posts, friends, and applications, as well as untagging all pictures, and deleting the account.
Dan: My account was deleted. When I reactivated it, I realized that everything was deleted.
Jake: You were Facebook Bombed. Someone must not like you.