Social proof is the mechanism behind herding. When you are uncertain, watching what others do is a reasonable shortcut, and markets keep you permanently uncertain.
Online it is easily manufactured. Screenshots, follower counts, and a hundred replies agreeing all create the feel of verification without any of the substance. A coordinated pump is social proof used as a weapon: the visible enthusiasm is the product being sold.
Ask who benefits if you act. Ask whether the people agreeing have independent information or are simply repeating each other. Ten copies of one opinion is one opinion.
Related: herding, authority-bias