I connected to Wifi (using a HTC Desire using Android 2.3) and a friend used an app (I think it was on an iPhone) to display information about devices connected to the Wifi hotspot. I can accept the MAC address being available but isn't having your IMEI number publicly available make it easy for people to do negative stuff like clone it, then fake a phone on the same network with the same MAC address etc? Or just report the phone stolen by phoning a network and giving the IMEI number? Why is it visible anyway? Can I change that field for the purposes of Wifi connectivity?
Note: I am in no way asking here for information on how to change the IMEI number of my phone - I know it's illegal in many places, and I agree with the law. I just don't see why the IMEI number is relevant in this situation.
Update - to answer your questions/comments:
The Apple app is called Fing.
I saw the app running; my friend is not teasing/lying.
I'm 99% sure I was running the latest version of stock Android on the Desire, and not Cyanogenmod (which I later switched to).
I can't see that it's possible to turn a MAC address into an IMEI address.
The network uses WPA2. He wouldn't have had time to crack it. I'm not aware Fing has a live, free, online WPA2 cracking capability.