That being said, one I would like to point out is the "Forged" affiliation certificate.
In this case The certificate below was presented as proof of affiliation to "The International Air Cargo Association" (Whatever the Hell that is).
Anyway, at first glace it looks (somewhat) legit.

At closer inspection however, you will see that the "Pertinent" information doesn't quite match in intensity of color OR font. Additionally You can see some spots where the original text was cleared out (after the scan to clean it up) and the substiuted text was added. This is most notable on the line that states "This is to certify that" as you can see portions of the bottom of the text is erased.

The moral of this story is that just because they have certificates and Logos don't assume that they site is legit. Do some homework.