Is anyone else getting strange private messages from friends? They are cordial but nothing like I would expect from these people.
Probably just your friends. If there isn’t a massive amount of speculation on a tech site or something soon after something like that happens, I doubt it’s system-wide.
Or maybe it’s your account that’s hacked and your friends are WTF-ing at you… 
Check your friend list for duplicates. A former classmate of mine had her FB page cloned & the creep started sending out friend requests to everyone on her list. As soon as I accepted the new friend request, I started getting weird chat messages. I figure it was Nigerian scammers.