Facebook missile

Someone who posts or shares certain posts on Facebook (usually derogatory or insulting) with the intention of a targeted person seeing it. (Target being someone in their life)

"Karen is such a facebook missile, we all know who she's talking about when she shares posts about unemployment"

Post digging

Sharing something on Facebook with the intention of a certain person seeing it (usually an insult)

I'm so sick of Michael post digging, everyone knows who he's targeting.