Pokemon Go appears to be using their new Adventure Week event to test out a new way of fighting back against accounts associated with third party trackers and other means of "cheating" the game. Pokemon Go Hub is reporting that Niantic Labs has allegedly flagged certain accounts deemed "malicious" to prevent them from seeing rare Pokemon spawns. Basically, if your account has been flagged, you'll continue to see to common Pokemon like Rattata or Pidgey, but harder to find Pokemon won't appear.
The new system appears to be Pokemon Go's latest effort against third party tracking systems. Most third party trackers use bot accounts to obtain location data about certain Pokemon, which it then passes on to the people using the tracking system. By flagging their account and preventing them from seeing rare Pokemon, it basically hinders the tracking system from working properly. The logic seems to be that by preventing trackers from seeing rare Pokemon, spoofers won't be able to hop from place to place sniping rare Pokemon.
What's more unclear is whether Pokemon Go is using the new form of punishment against any other "cheaters" like GPS spoofers or folks with multiple accounts. Spoofers that target gyms with multiple accounts is a much bigger problem in Pokemon Go than tracking systems, especially as most of the larger tracking systems have been shut down by the threat of legal action.
We'll have to see if there's something more to this new anti-cheat method is effective, or if this is just another futile effort on Pokemon Go's behalf. Meanwhile, Adventure Week runs through this Thursday, so get out there and start catching those rare Rock-Type Pokemon...if you can see them.