Nothing like a simple webserver access log and an excuse to lure a huge amount of people into sending you telemetry pings, eluding to their IP, its location and service, and several other details about the device.

Also, you know every time someone newly connects to a wifi hotspot. Along with google maps' and google android's multi-pronged endevors to map all the wifi hotspots SSIDs, MACs, and geographical locations, this has become a sort of side-channel spying and location tracking data collection tool.