A 17-year-old from Nebraska and her mother are facing criminal charges including performing an illegal abortion and concealing a dead body after police obtained the pair’s private chat history from Facebook, court documents published by Motherboard show.
correction: it was both! fedbook chat also supported xmpp at first, they never federated but you could at least use it with a jabber client. then when they had enough market share they killed it.
fun semi related fact is that whatsapp, at least a couple of years ago, was using modified ejabberd (ie an xmpp server) as the backend - so arguably they helped with EEE too.