Sharing something before checking it is lending your name to a stranger’s rumor.

A repost is not neutral. Whatever account it started on, once it goes out from you it carries your face and whatever trust people have in it. If the claim turns out to be nonsense, you are the one your friends remember believing it. You borrowed a stranger’s story and signed your own name to the loan.

Give yourself a thirty second rule. Before you pass something on, look for one other source, or check when the thing supposedly happened. If you cannot find either, let it sit, because nothing true stops being true in half a minute.