The asterisk(*) is used as shorthand after 'anyone' or any other indefinite pronoun to clarify that you're speaking ONLY to the persons present on whatever social media platform you're posing the current question, which avoids constantly having to specify "anyone ON HERE" and thus avoiding smart-arse replies.
Q "does anyone think that David Moyes is a great managerial appointment?"
A "I'm sure some people (like his mother and his wife) think he's a genius; I, however, think he's fucking clueless"
If we correctly use the asterisk, we should expect the following, much more concise, response:
Q "does anyone* think that David Moyes is a great managerial appointment?"
A "Nope, everyone* thinks he's fucking useless"