As an MIB/MISB collector these "reissues" are balls. Thanks to a lot of research I can be pretty confident that I am buying or own a genuine item.
I often report the fake sellers to e-bay and it usually works. However, if a seller specifically has KO in their item description then its a little harder to have any weight to get the item off.
I think someone from Hasbro should be on e-bay daily because it is a breach of copyright, although I have heard that Hasbro may be getting something from these fake reissues without having to produce them, but that was many years ago.