calling a note due

[Patty West]

Hello,

I've been hearing over the past few days that buying "subject to" now days is very risky. That banks now more than ever are really cracking down on this type of thing and calling loans due. I don't really see why a bank would do this. If payments are being made, why would the banks care who is making them.
This word of caution came to me from a title person. They say it is dangerous.
What exactly are the dangers?