Isn't MD5 subject to certain issues? The term 'collision attack' comes to mind where two values can produce the same hash. Presumably this sort of weakness means that it's possible for innocent images to be caught up in the dragnet.
And as for anything to do with capabilities provided by 3rd parties, will those 3rd parties be accepting responsibility for any false positives or negatives found as a result of using their systems? Will those using said systems face any consequences if/when problems occur?
Or (as I would personally expect) will everybody get off scot-free, and all because it's 'for the children'?