Apparently, there is Spoofer software that can't be detected today. The proof is at today's Pokémon Chicago Fest. In order for the crowd to spin PokeStops in the park, they have to first scan in a bar code on their ticket. This clearly is an implied message that they can't detect and stop spoofers. How about if Pokefarmer create a non-detectable Spoofer program???
It's not the spoofing getting you banned https://www.reddit.com/r/PoGoSpoofing/ There's a whole community dedicated to spoofing using normal spoofing software (FlyGps ect..).. Notice how no one complains of bans.. Feeding pokemon Raspberries is actually spoofing. Nintiac clearly had no intentions of banning spoofers as they are implementing it in their game.