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."
by Stop Drive By Friending January 22, 2009
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.
by Mike in Buffalo June 01, 2010