Man in the Middle attacks are so easy and cheap to set up. Just use a few wireless access points, pop them up around town, install something like Jasager and a 3G dongle. Phones like to connect with known networks and will happily connect with your rouge access point, if you tell them that you are exactly the ap they are looking for.

So, any system that claims to be secure must factor in MitM.

More information on this, and how easy it is to trick devices can be found at Troy Hunts website [0] and at Wifi Pineapple [1]

[0]: http://www.troyhunt.com/2013/04/the-beginners-guide-to-break... [1]: https://wifipineapple.com/