I am noticing an eerie pattern in the home page. Some new users(registered for couple of days, some are unregistered) answers a string of questions within a particular time frame (say 1 hour), then vanishes. They come after some days to answer questions (usually in bursts), others don't come at all. The answers are particularly of 3-4 lines with no references whatsoever (most of them are opinion based answers). Is it good? How to deal with such users? How to handle such situation?
Note: I haven't named any users and do not have any ill-intentions towards them. I am not targeting any user for such activity. I am just shedding some light on this situation and seek appropriate measure.