as others said, it can be obvious if one account is used to share the same sentiment. one other obvious one I've seen is when batches of similar posts for reco

as others said, it can be obvious if one account is used to share the same sentiment. one other obvious one I've seen is when batches of similar posts for recommendations in category "X" have each received a reply, usually days/weeks after the original submission, all from different users, posted around the same time, recommending the same product