Amazon appears to have stopped a strange plot that used phones in trees to game delivery route assignments. Contract drivers talking to Bloomberg said that they’re now getting more routes even when they’re miles away from the Whole Foods locations that had been hubs for the scheme. The tree-borne phones have vanished along with the people lurking around them, one Chicago driver said.

The tree-phone move reportedly exploited the behavior of the Amazon Flex dispatch system. Rogue drivers synced their phones with those in the trees, helping them snap up deliveries that would otherwise go to competing drivers. As Flex drivers are gig workers who get paid by the delivery, this was potentially lucrative — much to the chagrin of drivers who weren’t involved.