The posts on Twitter, Facebook and other sites are imposing a real-time test of Silicon Valley's much-touted rules on handling election misinformation and premature claims of victory.

Twitter and Pinterest announced the new initiatives just before the first-in-the-nation Iowa caucuses on Monday.

In the coming weeks, the group -- along with some 400 other organizations and individuals -- will launch a media literacy campaign of sorts, focusing on helping young voters identify misinformation and suspicious sources online.