Sign out of all devices

There is no tool available for determining connected devices or disconnecting devices. 

You can try contacting Support - at one time in the past they had the ability to "reset" an account, which would log out all the devices.  It isn't clear if they still have that ability (or are aware of it), but it's worth a try.

I'm having the same problem. I need my account reset to log out of all devices. I think I didn't log out at the hotel I was stayed at. Were the support team able to reset the device?

Have you contacted support to find out?

They're not able to help. I called and spoke with 2 reps.

The best you can do is change your password. Overtime maybe it will reset.

@bcbsncjlj Will you please stop giving this same crappy advice that you KNOW doesn't work because you have been responded to in many, many threads that your advice had no effect on this issue. Resetting the password DOES NOT WORK. Resetting the user name DOES NOT WORK. If you don't have anything useful to add to the conversation why do you keep chiming in with junk advice?

Like I said, overtime, it may require a password reentry. Some software updates will ask you to re-enter your password.

@bcbsncjlj but in the meantime, the people who are at the cabin we stayed at have access to buy ppv on our account. For months. Who knows how long? I have not needed to log back in to my smart tv at home for years. You don't know and your advice doesn't provide any solution so please stop.

That's because there really isn't a good solution to this issue. The best you can do is change your account password. Eventually those other devices will need to login again, and then they cannot. Of course, the ideal solution is to log out on any "guest" devices before you leave, but it's too late now. 

I'm in the same boat, but I am positive that I logged out of my friend's tv when I left.  The fact that it still thinks I am logged in is so incredibly frustrating. AND A HUGE FAIL ON ATT/DIRECTV's part. Why can Netflix help me but you can't??? And I am paying how much $$ for this incredibly unhelpful customer service experience?? Time to cancel people.. We can get pretty much everything we need from other providers who are much more hip to the times. 

The big fail unfortunately is on your side.

@bcbsncjlj it was only a matter of time before your comments degenerated to rude, as I see throughout this site that they always do. Your post has been flagged as inappropriate and unhelpful. If humans were perfect, customer service wouldn't be needed, would it? In leaving the cabin, I had to make sure it was clean, per their rules, that we packed everything, the dogs were fed and walked before we got in the truck for home, etc. The last thing in my mind was the friggin TV. You have added nothing to the conversation but insults and unhelpful advice that doesn't work. JUST STOP TALKING. Are you some sort of last word freak or something? The failure is definitely on the part of the service provider. This happens frequently and AT&T should position themselves to be helpful. In fact, they previously provided the ability on the app for users to logout of all devices. Why would they remove that function in app updates? Perhaps it didn't work either. Poor functionality should be addressed and corrected. And someone should relieve you of your duties here.

@bmstanifer 

Duties? We are just customers on a public forum doing this as an act of volunteer. We are not assigned duties, nor are we required to spend a certain amount of time here every day assisting people like you. 
If you don’t like the answer given, go someplace else. 

They have never provided a tool to logout of devices. We understand your frustration, but the responsibility is on your side. The best you can do is change your password, and eventually the active device will require a sign on to continue. Sorry for your frustration, and your rant is understandable.