Anyone know something about this broker agent firm

Rank: Monkey | banana points 42

Name: Scot trade
I first know it via chinese google page,
later i see someone around me buy US stocks through them,
they(scottrade) made huge profit from this business.

I looked up into some law files and found that this business may be illegle here without register at local securities supervision committee, or could say there is a law vacancy.

I want to know more this kind of firms, anyone introduce me some. Thanx.