Always Take a Credit Card - No Compassion Required

I must not be reading enough customer service skills tips because I seem to always get burned by the same type of guests. I try to show some human sympathy towards people in trouble and they only turn around and bite me in the ass. Here's what happened this time:

This guest checks in with me on the night shift. He's a guy I've seen before because he's a regular at the hotel. He's not the best dressed guy and he's usually a little dirty and smelly but I give everyone the benefit of the doubt and he seemed nice enough. He's got a prepaid reservation through Priceline or Hotels.com or something like that so it wasn't really necessary for me to take a credit card from him.

I always try to get a credit card from people because you never know what they will do in that room and you have to have a way to penalize them. He couldn't provide one. I let it slide...

He smoked in the room.
Ruined the whole room and we can't sell it for two days.
We are a nonsmoking hotel and there is a huge fine for smoking.
I get chewed out.

So much for being compassionate.