A lot of people post a lot of shit on social media. Especially when it is about politics, conspiracy theories, or other highly polarizing things, a lot of people don’t even make the effort to check their source.
I’ve called out several friends in the past, when they posted something with an untrustworthy source, or worse things that are obviously false. What gets me each time, is how often people respond in a careless manner, saying things like: “It was just a link, I can’t check every link I copy” (well maybe you should copy less links) or “Well I thought it was interesting anyways” (so why didn’t you point out doubts about the source along with the link?) or “I’m not a newspaper why should I check my sources?”
The thing is everyone who spreads a link, or a picture, or something he/she has read somewhere on one of the social networks has reach, and with reach comes responsibility – You might not have the reach of a newspaper or tv station, but usually because people value information from a peer more than from media outlets, there will be people listening, and just like you there is a high chance they don’t check the source of the story – and they spread it without informed comment. In the times of viral/social media, you are a source, and thus responsible for what you spread.