A person who pesters you on Feacebook, constantly sending irrelevancies or begging for a connection.
This is the 5th inconsequential message I've received from John today; he's become a facebookworm.
After I rejected Karen's connection request on Facebook, she sent connection requests through 3 other networking sites. She just doesn't get it. What a Facebookworm.
A person who clearly spends too much time on Facebook, to the detriment of alternate social activities, or even conversation with the person or group they are currently with.
A Facebookworm could be a person in a bar or cafe , staring intently at a smartphone and "liking"away as as real life evolves around them.