With USB-C, this is going to get much, much worse. Apple, Google and HP now have laptops that can get juice from every charger.
However, the protocol for that (USB-PD, Power Delivery) is a digital protocol. So companies that used to build purely electronic chargers will now have to build or more likely buy firmware for their chargers. There's bound to be bugs in there, but we're talking about chargers that can supply up to a 100W of direct current.
I dare not guess how much houses are going to burn down because of crazy power supplies.
Personally, I'm only buying cables and chargers that have been tested thoroughly. You can't trust Amazon reviews, you can't trust big brands, you can only trust guys like Benson Leung and Nathan K., who whip out the protocol analyzer and the benchtop electronic loads.
This is a real good source: https://docs.google.com/spread...
And this is the Google Plus page, where they post an analysis every so often: https://plus.google.com/collec...
I second this, after having done considerable research on this over the past week. Be careful guys, many well reviewed chargers with 4+ star rating on amazon by lay people (like me) were tested and shown to be outright dangerous.