you do know that you get convicted if some website loads some child porn in some invisible iframe without you knowing if the cops can find it in your browser cache? Or, to take it somewhere offline, that you get convicted if you buy something off ebay and when you try to register it to your name and it happens to come out that it was stolen.
You do know that in most jurisdictions, receiving stolen property requires the keyword: "knowingly"?
How are you going to prove your own 'ignorance'? Prove the non-existence of your knowledge. Good luck with that.
All it takes is some prosecutor who thinks he can convincingly prove that you did 'know' to cause a lot of trouble for you (even if you ultimately win).