We know Libs don't understand market concentration, exploitation, and abuse, but they also don't really understand freely competitive markets with perfect information either.
They keep saying that 'the individual is king' - that he is supreme. They confuse individual exchange - which happens like on Craigslist or at a flea market and market behavior in general.
Anyone who has tried to buy something in a real market knows that the prices and quantities are pretty much set. Your action means nothing to the larger market. The more the market decisions are set at an appreciable distance to the consumer, the less the consumer feels like his opinion means anything. We all become cogs in a machine.
So what did cause - say - the organic revolution? How many times did a hippie in the sixties complain to Safeway to bring in organic produce? And how many times did Safeway say 'hell, it's unprofitable, we will go out of business'. It took probably decades for people accustomed to market forces to make small incremental changes towards organic foods in a few select places.
So we see here violations of Libertarian principles. First, the consumer is irrational for not wanting buy healthier food. The store owner is ignorant of the demand for organic foods. There is no market communication between the demanders of these foods and the supply. Years of habit and culture lock out the market for organic foods: individuals are meaningless. Also, somewhat less obviously, people cannot start their own stores (although many tried, of course, but the result was sort of disastrous).
The same with ingredient lists. Why didn't stores list the ingredients and expiration dates of their products? The answers are the same. People are irrational, store owners are ignorant, and the market does not communicate the desires of the consumers to the producers.
This is why the government requires stores to list their ingredients and put expiration dates on their products.
Similar stories can be said about many consumer and occupational safety regulations, about CAFE standards and the rest of it. In fact, if one had an open mind, it would be obvious.