Pokémon Go developer Niantic has repeatedly made it clear that the company disapproves of players who use unofficial third-party software to boost their experience. Now Niantic has allegedly come up with a unique form of punishment. Rather than being able to detect and catch the fame’s full roster of pokémon, these so-called cheaters can only spot the most common creatures, like Pidgey, Rattata, and Zubat.

This “shadowban,” as spotted by The Next Web, effectively shoves players into a neutered version of the game, where they can’t see rare spawns. Last August, Niantic began issuing permanent bans to players who violated its terms of service. Players were punished for acts such as using emulators, using modified or unofficial software, falsifying their locations, or accessing Pokémon Go clients or backends via third-party apps. The choice was controversial among players, as it also crippled third-party services like PokéVision, a map that helped users locate pokémon.

Users on The Silph Road subreddit, a community of Pokémon Go players, say affected accounts aren’t being banned outright, they’re just being “flagged” as illicit. “Huge numbers of bot accounts were being flagged, though many were still operating normally,” reads a post on the subreddit. “It was initially suspected that accounts were flagged due to using deprecated API calls to access server resources from Niantic's private API, which may have been true, but it turned out not to be the only reason illicit accounts were flagged.

“As of this moment, it is still unclear what behavior is tipping off Niantic that an account is not legitimate.”

As reported by our sister site Polygon, players using bots or third-party tools have encountered warnings like this:

The Silph Road post says not all bot accounts are being flagged. “As bot accounts (which power ‘scanners’) are being flagged, some scanners are only able to show common species. Others have shut down temporarily, pending a workaround to the anti-botting measures, to preserve their accounts from being shadowbanned.”

We’ve reached out to Niantic for comment, and will update accordingly.