I am new to this forum. Forgive me if I am posting in the wrong thread.
We recently shifted apartment and during the course, we lost our Roku 3 player. I disconnected it from my account as per the instructions in Roku site. Luckily we have the serial number of our Roku noted. Is there a way to find the IP address the Roku is connected (assuming someone is using it) and track it down? please advise.

Roku won't/can't give you information about where a device is connecting from. There's no way for you to do it either, as far as I know. 

Do you think your Roku was stolen? If you were moving to a new apartment, didn't you take everything from your old apartment?

Maybe tracking it down for return isn't viable, but I would think that Roku could do something to disallow a stolen player from being used on its service, no?