How can hacks effect someone else's game?

Question

For example if someone traded a hacked Pokemon to my game would it effect my game. If they gave me hacked O-powers would it effect my game. Also would someone having a hacked game effect my game through passerby or whatever (doubt it but still).
Traded Pokemon, O powers, friend safari, etc

Comments

Traded Pokemon wont.

Answer 1

They can't

• Hacked Pokémon will not affect your game, but if they have illegal Abilities or moves they cannot be used in Wi-Fi battles.

• Even if you are given O-Powers that were obtained with a cheat, they will work normally, and will not affect your game.

• Even if you play with someone with a hacked game on PSS, it cannot affect your game. As I said above, Pokémkon with illegal traits cannot participate in battles, and hacked Pokémon don't affect your game anyway.

Source: Experience