Just curious...

I've seen a few posts of people complaining about 'hacked' stuff. I'm just curious to know how they determined that stuff is 'hacked.' You CAN'T use a regular Diablo Item Viewer - of course that'll show some stuff as 'hacked' because of differences in the game (Monster Levels, etc.). Maybe they're using an Abysmal Item Viewer?

Any explanations are welcome...