Yes you can, if you part with money for something you know nothing about then that's your fault.
The fact is we can all sit and moan about people breeding shit to shit and so on, and fair play for exposing the jokers that breed from unproven stock. It's always going to happen though whilst there is people daft enough to buy stuff in that they know nothing about.
You wouldn't pay good money for a house without getting it checked to see if it's structurally safe first would you? The same applies here, if you don't know the background of the pup, then don't buy it! It's simple.
Mos