Don’t do it. The access card used in your DIRECTV receiver is tied to your account and in some cases tied to the specific model or receiver ID of your DIRECTV receiver. If you pop out your card and try to put it in a friend’s DVR or receiver, two things will happen. First of all it probably won’t work; you’ll get a message on screen saying there’s a problem.
The second thing is that the receiver will try to contact the servers at DIRECTV to let them know. If the receiver is connected by internet or phone line, the folks at DIRECTV will know of the situation fairly quickly. They’ll assume it’s a mistake at first and probably just watch the receiver a little more closely to make sure everything works right… but at some point even if it works they’ll assume that it’s a fraud attempt. The thing is, it actually is a fraud attempt and it’s part of your customer agreement that you won’t tamper with the equipment.
So, there really isn’t an upside. There are a lot of downsides, and if you think DIRECTV’s too big a company to notice what you’re doing… there have been way too many reports of honest people who have gotten a call from DIRECTV’s fraud squad. I’ve personally known people who have faced multi-thousand-dollar bills and the threat of litigation for doing something as simple as putting a receiver in a location where it doesn’t belong. Don’t risk it, it just isn’t worth it.