You'd best be wary. They can still be hacks. I once obtained a Shiny Lugia (in a Nest Ball - I'm not kidding, a NEST Ball) that claims, from the rater, to have perfect IVs; the thing that gives it away is the OT, which links to a Youtube page about hacking. I've never allowed it to see the light of day since. I don't delete it, I just let it sit there to show to anyone who wants to see what it looks like.
I also knew it was a hack before I got it, and I sent the person two Enigma Berries as a thanks for getting that one out of circulation.