This is the sentence judged to be neither cruel nor unusual to certain types of people who request to be your friend on Facebook. These types of people include people you "knew" in middle school or high school, people you "recognize" from a class, or someone who paid close attention to you during your introduction at a recent party. It may also include people you don't want knowing your general information or what you do from time to time, which may include family, ex's, or chaunces.
What happens to these people is you never respond to their friend request because you don't want to be their friend and you don't want them to either 1) know you declined them or 2) be able to request you again. They then spend the remainder of their life pending, while you hope they assume you have a buildup of requests that you generally don't respond to.
1) Someone friended me on Facebook that I know only because I hear him breathing heavy in my PSYCH 111 class everyday, he is definitely pending for life.
2) I like posting my drinking stories on my status all the time; so sorry Mom, you're pending for life!
3) Alex: Yo Ben, isn't this that bitch I said 'hi' to last week who ended up puking all over Evan's new couch like 30 minutes later?
Ben: Ya I think so, why the hell is she adding you on Facebook?
Alex: I don't know bro, I never thought she would be able to remember me, she is for sure pending for life.