IMEI number publicly displayed whenever connected to Wifi 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.
I don't know how one would garnish the IMEI information over WiFi but what I would suggest is ask your friend what application they were using and then try to find an Android version of it. The developer that makes the iOS application might make an Android one, too.