Another common example of a free market is the universal practice of children swapping baseball cards-the sort of thing where you swap "two Hank Aaron[s]" for "one Willie Mays". The "prices" of the various cards and the exchanges that took place, were based on the relative importance that the kids attached to each baseball player. As one way of annoying liberals we might put the case this way: liberals are supposed to be in favor of any voluntary actions performed, as the famous cliché goes, by "two consenting adults". Yet it is peculiar that while liberals are in favor of any sexual activity engaged in by two consentings adults, when these consenting adults engage in trade or exchange, the liberals step in to harass, cripple, restrict, or prohibit that trade. And yet both the consenting sexual activity and the trade are similar expressions of liberty in action. Both should be favored by any consistent libertarian. But the government, especially a liberal government, habitually steps in to regulate and restrict such trade.