I don't believe protein powder is regulated for quality by the FDA since it's a supplement. This actually allows sloppiness in a LOT of bodybuilding products. Hell even bodybuilding.com was forced to pay a big fine due to, er, suspicious steroidal compounds in their products iirc.
The above is, quite possibly, one of the biggest issues with the fitness industry. Worse than the shit programming, the crappy equipment, long term gym contracts, Crossfit injury prone boxes, etc.
The reality is that these companies can lie. Flat out fucking lie, and all the need is an asterisk that says "these statements have not be verified by the Food and Drug Administration." No oversight, no accountability. It's a fucking shame. Plus, if they use something they shouldn't or sell a shit product, the company can tear everything down and just change their name. Happens all the time.
Seriously, I'd rather be on D-Bol with no liver support than 95% of the shit on the market. I know what it does, I know the affects, and I know how it works. Before you waste a dime on a supplement, hella spend the time researching it.