You are speculating that the MM's are involved in a conspiracy. MM's anymore do not personally operate the trading platforms/ with the exception of potentially rare occasions and special circumstances.
Now if the MM's were trading the stocks themselves all the data would be recorded and be able to be spotted as cross trading which is very illegal.
Anyway the markets are handled by and ECN these days, a software program with algorythms that mimick what a personal hand would do under buying and selling pressure.
But under your scenario it would end all the short/nss theory put forth by your fellow longs as they like to be called.
Anyway ANDI does in fact have NO significant fails to deliver :)
Market Data 
Markets 
