How do you flag potential "fake" users

How do you flag potentially “fake” users that promote services, you know like the classic one in which every post is about recommending 1 particular broker and that reads like it’s taken off their website?
Wasn’t sure who to ask or where…

There is a cleanup link on every post. It is in the lower left hand corner. The icon is a triangle with an exclamation mark.
I use it regularly.

yep that triangle at the bottom of the post flags it for the mods. I use to just flame people but now I have it takes less effort just to flag them.

Thanks for trying to keep our site clean from these people

Cheers guys.
See personally I think there is nothing wrong if people working for Brokers post on the site, as long as it is not just for promotion of the broker but also to give an insight into brokers or maybe give a different prospective etc.
But all posts just going on about how great this particular broker is (ironically usually bucket shops) is kind of a joke…