Hide-and-seek

China had 688 million Internet users by the end of 2015, with more than 90 percent using smartphones.

A recent report by think tanks FutureX and the Data Center of China Internet (DCCI) showed that around 150 million Chinese used online catering services as of June 2016. The figure rose by 32 percent in six months and keeps growing.

The country has strict food safety regulations, but the proliferation of kitchens and restaurants riding the e-commerce boom makes supervision more difficult.

Last year, the national legislature amended its seven-year-old Food Safety Law, adding provisions to govern online vendors.

A report by the Ministry of Commerce in September said around 8,000 unlicensed online eateries were ordered to close in just two weeks in late August to early September, after an unannounced city-wide food safety inspection.

An anonymous worker at one of the "Big Three" said many vendors simply reopen on rival platforms, a phenomenon that discourages platforms from closing down "problem" vendors, especially the popular ones.

"The three platforms are fighting for market share. If one strengthens supervision while the others do not, vendors jump ship taking their customers with them. The one who abides by the law loses," he said. "Technologically speaking, it is not a big deal for a platform to kick out unruly vendors. But does it really want to?"

The DCCI report says the "Big Three" account for nearly 90 percent of market share among young office workers, catering services's main users.

Confronted with Xinhua's findings, both meituan and ele.me declined to comment. Baidu repeated that it requires all registered vendors to post authentic licenses on their web wage and runs regular checks to ensure compliance.

Fu Weigang, a researcher with the Shanghai Institute of Finance and Law, says the proliferation of "problem kitchens" has everything to do with lax supervision of online platforms, which sacrifice food safety to cut staffing costs and reach more customers.

Fu suggested that the authorities mobilize the public to become informants on vendors and platforms who do not play by the rules.

"Informants should be rewarded so they are encouraged to help law enforcers spot violations," he said.