I'm not saying any tracking is great, but a couple of things here. I cant remember when if ever I logged out os steam and this is just shared with friends right? Not sure if this is a nothing burger or not.
>>uberma+(OP)
In this context, 'Logoff' triggers whenever the socket disconnects. So every time you shut down your PC or put it to sleep, that timestamp is updated and broadcast, even if you never explicitly clicked 'Sign Out'.
>>xmrcat+o
Still, I dont run steam on my laptop and on my gaming system that I let my kids use it never sleeps and restarts only as a result of windows update. The monitors do turn off but unless that counts as sleep as well I dont really see how this would be a thing at least as how we use steam.