Here's proof:
http://www.mkyong.com/java/how-to-get-mac-address-in-java/
It's a simple Java script. If Java script will do it, anything will do it. Any kind of custom code you can't possibly imagine will deliver your MAC address anytime anyone that has the ability to ask for it wants it. It's like a $3.00 whore, only they don't have to pay the $3.00. It's free. It's available. It's right there, just waiting for the right person to come along and ask for it. Easy. Simple. Cheap. Free, even. Free MAC Address, just there for the asking. It would be less obvious if you wrote your MAC Address in 6" letters and wore them on your forehead, like a sign. You could even decorate that MAC Address sign on your forehead with Christmas Tree lights, and even then it would be less obvious than the availability of your MAC address to anyone that wants it online. Just there, waiting to hand it over to anyone that asks. Like a free whore, as I said earlier. Your computer is a free whore, and hands out your MAC address to just anyone.
Have you all got this yet, or do I need to continue?
Pay attention, kiddies. This is the only person in the whole thread that knows anything. Every single other person is wrong in some way or another. I deleted most of my post because it wasn't "friendly" enough. Just too much wrongness in this thread for me to handle; like a loud discussion on the short bus, there are too many 'tards and not enough time.