"[Question] retaliation for gym attacks, ok or not?"

#PokemonGO: Today some mystic players from a neighboring town took out 5 valor level 10 gyms in my town. They then proceeded to use gastly strat to build them up to high level mystic gyms.Is it ok to go to their town now and take out their level 10 gyms? I won't stoop as low as to gastly strat the gyms, but taking them out with my little band of valor players could be fun. To be honest I am getting a bit sick of constantly chucking potions/revives away. I think it time to put them to good use.Or would this be considered bad play?Edited: a lot of replies wonder why I should think this is wrong. To clarify, I would only be taking them out as retaliation, as mentioned in the title. I don't need to place my Pokémon in the gyms I will take out. It's purely revenge.Thanks for the support anyway. If nothing changes in the comments we are going to raid that town! via /r/TheSilphRoad http://ift.tt/2qcWac9