Matt Ygelsias at Slate's MoneyBox argues that the "clear implication" of the efficient market hypothesis is that there is a "strong case for paternalistic regulation" in financial services.
Ygelsias doesn't go into detail about what the paternalistic regulation would be or how it would work. But I get the sense that he is trying to make the case that regulation should nudge investors into low-cost, diversified index funds.
The logic here is pretty straight-forward. The efficient markets hypothesis holds that market prices accurately reflect all available information. One implication of this is that it's extremely unlikely that investors can beat the market by picking stocks.
In fact, picking stocks or hiring professional money managers is likely to be a losing strategy for most investors. So shouldn't regulation discourage this sort of thing?