Late last night, @TheCapitolPN on Twitter was hacked, and the rebels managed to post a very cryptic tweet, before the Capitol caught it and deleted it a few minutes later.
The letters at the end are the four notes of Rue's whistle, and the 'inspct_elmnt' hint encouraged fans to check out the source code of TheCapitol.PN website, revealing this hidden message:
THE MOCKINGJAY LIVES
You silence our voices, but we are still heard.
Seems like the rebels are really getting the hang of this hacking thing! We can't wait to see what else they've got in store...