Maybe I'm reading this different than everyone else but I interpret his question to be around staying under the radar. Buying MOs for points is not illegal. If you really want to stay under the radar do about $1,000 a week. That's a nice 50,000 points.

I suggest also that you don't BS or lie to the cashiers or tellers about it. If you tell them it is for points and then later have a government entity get involved you will not have to play games. Keep good records and be prepared to share them if you need to. The truth is always your strongest defense unless you are a criminal.

In my opinion your real risk is the bank you are depositing to will shut you down as a fraud/security risk. Be sure you can live with that account being frozen for a few weeks if they decide to close it on you. They can sit on your money for something like 10 business days AND be real slow about getting you a check.