Say you criticise someone in a blog post. If that person posted a response to your criticism then under this proposed law you'd have to link to their response. How stupid. Showing a wisdom that the Europeans could learn from, in 1987 Ronald Reagan axed the more limited US equivalent for broadcast media called the Fairness Doctrine.
I see a proposal like this as an obvious violation of free speech because it compels someone to speak when they do not want to. If you do not want to link to someone (and linking to someone is a form of communication) then you shouldn't have to. The people in European countries really have no protection against this sort of nonsense. European nations really could use strong constitutionally guaranteed freedom of speech. But in Europe the concept of rights has gotten so confused with the concept of entitlements that when they sit down to think of ways to protect rights they inevitably instead end up coming up with entitlements that others become obligated to support.
What a bad idea. If a CEO wanted to respond to my criticism about some dumbass business move he/she made, I would love to link to it just to know they were reading my blog. But I agree with ParaPundit that what this could turn into is a situation where people made very few criticisms.