Nobody likes Cheaters and developers have been working on all sorts of ways to deal with them. The most obvious and probably the most effective way is to outright ban accounts that have been found to be cheating, but there exists other methods that could prove to be useful as well, such as the shadowban, which is what Niantic is doing to Pokemon GO cheaters.
In a post on Reddit, Niantic has confirmed that the gameplay of gamers who have been found to be cheating or trying to trick the system will be affected. While the company hasn’t explicitly stated that it is a shadowban, it sounds pretty much like one, although it is unclear if this is a permanent ban or a temporary one. Previous the developer was just perma-banning gamers.
According to Niantic, “We’re committed to maintaining the state of Pokémon GO and our community of Trainers. People who violate the Pokémon GO Terms of Service (including by using third party software and other cheats) may have their gameplay affected and may not be able to see all the Pokémon around them.”