probably. I have a shiny druddigon with 5/6 max IVs in a Luxury Ball that was sent over from Unova. Found it on the GTS.
There are several reasons I believe this to be hacked:
1. Its a shiny Druddigon 2. It has 5/6 max IVs 3. It was caught in Gen 5 4. I say caught because its in a Luxury Ball, and breeding in gen 5 would always result in the new pokemon being in a regular pokeball.
From my calculations, the chance of this being a legitimate pokemon is 10^-43%
A few. I was traded a 6IV Ditto, a few Pokegenned Pokemon like Aerodactyl and Charizard, a 6IV shiny Mewtwo that I won over Miiverse in a contest, and I suspect a 6IV shiny Ralts I got from the GTS is also hacked. Either way, it doesn't bother me- with the newfound simplicity of breeding and the higher shiny rate, they're barely unfair anymore- it's just the lazy way out now.
3DS FC: 2707-2741-9594 Pokemon Y Safari- Sunkern, Sawsbuck, Maractus