When you notice yourself losing connecting with people over Facebook; no comments, posts, or messages. You attempt to regain your dwindling friendships by commenting, posting, or messaging everyone on your news feed, in an attempt to let them know you are alive, and still their friend.
*Valkyrie term is referencing "call of duty:black ops" it is a form of reinforcement. In a Facebook Valkyrie you are reinforcing your friendships, by bombing everyone with comments, posts, and/or messages.
Jill:"hey, everyone at school says they barely hear from you now"
Jack:"ahh, dont worry about it, i'll call in a Facebook Valkyrie, and they'll all be fine."