Just tried it at home and loads fine from broadband too. That "Sito sotto sequestro" literally means "site has been seized", which of course isn't the case here; that page might indicate that the carrier has been forced to resolve that domain elsewhere, therefore all it needs is using an external name server to get around the block. I'm currently using one of Cloudflare DNS addresses and it loads just fine.

I don't use the (ex) national provider (Telecom Italia / Tim) however. Crappy service aside, they're well known for jumping every time the government tells them to, and happily filter a lot of stuff.