Exclusive: Congressional leaders were briefed a year ago on hacking of Democrats - sources
http://www.reuters.com/article/us-usa-election-democrats-hack-idUSKCN10N00D
Saw that a while back. There was a story that the Dems didn’t cooperate with the FBI investigating because they were asked to turn over all email addresses and passwords and didn’t want to do that.
Basically it’d be a plain view exception to a warrantless search and could lead to prosecutions. If, that is, they had something to hide.