"You keep on trusting him and believe that everything will turn out fine. But, every time he disappoints and hurts you and breaks another new record," 3271755890 wrote.
Other Weibo users posted that they had "lost all hope" of the market righting itself, and that the latest rout was "the start of China's financial crisis," while others called for corrective action by regulators and retribution for market manipulators.
A user called Laopuerchake wrote: "Some will say that today's A-share market is affected by the global market and the global market is affected by the A-share market so what you see is this cycle. It's never-ending. Perhaps now, our China Securities Regulatory Commission will say the same thing that they've always said: it is completely normal. Sigh!"
Read MoreChina woes take Asian stocks to multi-month lows
Following the announcement on Sunday that China's State Council, or cabinet, would allow local pension funds to invest up to 30 percent of their net assets in the country's stocks, equity funds and balanced funds, some Weibo users professed concern at the prospect.
A user called Yiqushiyinian posted: "Why is it that our country is allowing pension funds to access the stock market now at this particular time? It's done with a purpose and I am scared."
The Shanghai Composite fell more than 9 percent in intraday trading before closing down 8.5 percent on worries about the economic health of the world's second-largest economy. The smaller Shenzhen Composite lost 7.7 percent, while the CSI 300 index, made up of 300 A-share stocks listed on the Shanghai and Shenzhen exchanges, dropped 8.5 percent.
The Shanghai index, which had rallied some 60 percent between January and June, has now lost all of this year's gains.
"It is a key moment for China, with the equity market in free fall, the banking system increasingly starved of liquidity, rising capital outflows, and a rapidly slowing economy," IG's market analyst Angus Nicholson wrote in a note.