Clickfarms are a dubious business people rarely get a peek inside of, but accept as part of our everyday internet existence. We know companies pay bots to shower likes, emoji, ratings, nonsensical comments, and plain traffic on content in order to artificially boost online popularity and rake in ad dollars. Now, a recent raid in Thailand is giving another look at the underbelly of the bot industry.

According to the Bangkok Post, Thai police and soldiers raided a rented home yesterday near the Cambodian border, discovering an alleged clickfarm ring run by three Chinese nationals. Wang Dong, Niu Bang, and Ni Wenjin are said to have had metal racks set up in the house with hundreds of 5S, 5C, and 4S iPhones wired to computer monitors. In total, 474 iPhones, 347,200 unused SIM cards belonging to Thai mobile phone operators, 10 computers / laptops, and other assorted electronics were reportedly seized.

Officers originally thought the men were running a fraudulent call center, but the suspects said they were being paid to operate a vast network of bot accounts on WeChat, China’s largest social network. According to the Post, the trio of men said a Chinese company (which they refused to name) supplied the phones and was paying them each 150,000 baht per month (about $4,403 USD) to artificially boost engagement on WeChat for products sold online in China. The operation was reportedly headquartered in Thailand due to the country’s relatively cheap smartphone usage fees.

WeChat’s bot problem is not new. The platform has over 700 million monthly users, most in China; chatbots are legitimately used by brands to interact with clients, but unsanctioned ones run rampant, spamming groups and artificially bloating brand likes and follows.

The Bangkok Post says the men were arrested on several charges including overstaying their visas, working without a permit, using unregistered SIM cards, and, according to a later report also from the Bangkok Post, smuggling. Working without a permit in Thailand can result in a five-year prison sentence, or a fine ranging from 2,000-100,000 baht (about $58-$2,936 USD), or both.

Police are currently looking into how the men were able to smuggle so many smartphones into the country and acquire such a large number of local SIM cards, which are legally required to keep users’ records once activated.