drive-by friending 

the act of friending someone on Facebook, writing something mean on their wall, then unfriending and blocking them.

That jerk Shane is on Facebook now, so I did a drive-by friending on him.

drive-by friending by MichiganJ September 14, 2010

drive-by friending 

The sending of a friend request on Facebook or other social networking site without including any information on who you are or how you know the recipient.

There were twenty mutual friends listed, but I never heard the name before and they didn't include a note identifying themselves. So I rejected it as a drive-by friending.

drive-by friending by Mike in Buffalo June 1, 2010

Drive By Friending 

When someone you haven't spoken to in years sends you a friend request on Facebook, but doesn't bother to ever say "hello" or ask how you've been. When someone friend requests you on Facebook clearly only to increase their number of friends, and then there is no further contact.

"Man, this chick I went to high school with totally just did a drive by friending on me. She could at least say hi."

Drive By Friending by Stop Drive By Friending January 22, 2009