If the disconnected device is indeed suspicious, to keep your information safe, you should change your { -product-mozilla-account } password in your account settings. You should also change any other passwords you saved in { -brand-firefox } by typing about:logins into the address bar.
If the disconnected device is indeed suspicious, to keep your information safe, you should change your { -product-mozilla-account } password in your account settings. You should also change any other passwords you saved in { -brand-firefox } by typing about:logins into the address bar.