@dragosroua,
Actually this is a hard time for me too :D I am earning in steemit via posting and commenting! And now I have lots of competitors :D Some people upvote his own comment and trying to get the top to the comment queue! Or will provide cheap comments like you said!
Respect the way you think, personally I hate use flag, coz I am not much powerful and it will drain my vote power also! So, better the way you deal with them!
Cheers~