(Questions about the current state of journalism aside...) There is already standard journalistic practice for avoiding this: get a second, more reliable sourc

(Questions about the current state of journalism aside...) There is already standard journalistic practice for avoiding this: get a second, more reliable source. It can often be much easier to get a reliable source to verify information initially provided by a sketchy source than to get that reliable source to provide information in the first place. If you post unverified information that one person on the internet tells you, your work is indistinguishable from gossip, and should be taken as such.