Here's the situation: Henryk and Karsten are sitting around drinking beer and one turns to the other and says, "hey since we aren't doing anything let's take a powerful microscope and take apart the MiFare RFID chip." (this is complete fiction - well the beer drinking part - I wasn't there they could have been drinking wine for all I know.)
Compterworld has an article discussing the MiFare RFID tag hack. A RFID tag used by "Millions upon millions of MiFare Classic chips are used worldwide in contexts such as payment cards for public transportation networks throughout Asia, Europe and the U.S. and in building-access passes."
Hypothesis: "Hmm wonder how these MiFare RFID things work?"
Process: Take them apart
New Hypothesis: "You think there are any vulnerabilities in this thing?"
Process: Holy crap these things are as secure as my credit card data at the grocery store.
What I really want to point out here is that given time it can be broken. I have heard on multiple times from Vednors, Programmers, Engineers - our "insert name" can't be hacked, broken or abused for nefarious purposes.
Well boys and girls (equal opportunity) you are wrong!
Lesson to take away from this. Don't rest on your laurels (I am in Athens, Greece - seemed like a good phrase). Keep innovating - while today it looks like it can't be broken, tomorrow some kid might try to put it in the microwave.