Twitter users knew something was up last week when they noticed a bunch of accounts with “Amazon FC Ambassador” in their display names, saying things like “I actually do make a decent living working at Amazon” and “I can use the restroom anytime I want!” Suspicion was warranted: Amazon confirmed this week that it’s been giving perks to warehouse workers who tweet positive things about their employer.

The astroturfing campaign comes amid escalating public scrutiny of Amazon, driven largely by Bernie Sanders’ near-daily criticism of its CEO Jeff Bezos. Sanders has been bashing Bezos in an effort to draw attention to a larger complex of related issues, from wealth inequality to labor abuses to corporate welfare. Bezos is exemplary on all counts: his company’s labor practices are abhorrent, he’s excessively rich, and the public subsidizes his profits through taxes.

Sanders has been stressing the latter point of late. “Mr. Bezos continues to pay many thousands of his Amazon employees wages that are so low that they are forced to depend on taxpayer-funded programs, such as food stamps, Medicaid and subsidized housing in order to survive,” the senator said in a video last week. “Frankly, I don’t believe that ordinary Americans should be subsidizing the wealthiest people in the world because they pay their employees inadequate wages.”