This move is obviously motivated by politics and business. Berlusconi basically runs Italy like a corporation that he owns, and since he controls 90% of Italian media his interests don't align with sites such as youtube, Reddit, Digg, etc. that pose a threat to his business. What he's doing is what any (heartless..) savvy businessman would do: Cut out the competition. Of course this is absolutely terrible for Italian democracy and free speech.

It's nothing personal - only business.