Actually, any device that's connecting to the Groundspeak infrastructure to do anything, whether that's viewing the website, accessing caches through an app, or sending messages, will have an IP address that Groundspeak can record. You can't be on the internet without one.
I fully realise you can't be on the internet without an IP address however for example you are using the wifi at the local McDonalds or the local library, then the IP address reflects this. You are not able to be identified. In the same way that if you are accessing premium caches using the app, your user name will not appear in the audit log for the CO. Here poses another problem.
Lets not forget mobile dynamic IP and IP blockers, VPN etc etc