Is there, such thing, as biased CSM'S.... Any comment's!

I was thinking about finding away to record say 1,000 hands on an CSM'S and see if there was like a consistancy of +true counts after consistancy's of -true counts or something to beat it. I was told that csms can control the flow of the cards negatively or positively biased. Because for such thing to exist wouldn't there be rules about evening the biased out at predetemined time to keep the game fair... There must be some kind of gambling regulations that asm's and csms have to live by right...