It's a challenge for officials at all levels of government, including a state lawmaker in Utah who recently had to talk it out with someone he blocked.
Experts say such propaganda sows divisions within society by confirming beliefs. Facebook, Google and Twitter officials are testifying this week about Russian influence on the 2016 election.
The microblog service announced the move "effective immediately" ahead of a congressional hearing about Russia's use of social media in its influence campaign.
Former FBI Director James Comey publicly claimed ownership of a Twitter account Monday and signaled that he is about to rejoin a national conversation.
Trolls, bots and other mischief aimed at shaping the U.S. information environment have continued long after the presidential election even as Washington focuses on Facebook and Twitter.
Miscarriage, while widely experienced, is not often discussed in public. Researchers have turned to social media to see what people are saying about the topic and how much they're choosing to share.
"No one is born hating another person because of the color of his skin or his background or his religion," the former president tweeted. He was quoting Nelson Mandela, and it struck a chord for many.