Wifi has been fundamentally broken for a very long time and really should not be considered secure at all, which is why everyone has been pushing https for over the wire communications.
I can buy or make hardware to break almost any wifi network for sub $100 and a lot of people are still not patched from that wpa2 crack a few years back.
It is August and thus the season for security issues as all the hacker conferences are on, I would highly recommend checking out many of the deacon talks on YouTube from years gone by, elevator hacking is still one of my favourite topics