Completely cutting off another country would require participation of foreign countries, but I think we can at least get domestic ISPs to perform a substantial amount of filtering by themselves - and in the event of a putative "massive cyber-attack" (I'm not thrilled about the concept but there it is) a substantial reduction in harmful traffic can be consequential. And legislation is helpful on that point because the government can coordinate exactly what kind of filtering needs to be performed.
I suspect Lieberman's goal is to put this under his jurisdiction, under the auspices of formalizing and streamlining what is already a technical reality, under the spurious belief that his reign as senator will last past 2012.
This is speculative, but I don't think implausible:
Say that 1000 accounts on this server have been acquired or hacked by some group ( a particular foreign country, a cartel, mob, whatever). They are used to transmit messages not over e-mails but over your own private servers. Do you not suppose that it might be of a national interest (in this situation) that the otherwise private information on your server be examined?
Elliquiy's pm system generates the better part of a million words per day, right now. Even ignoring this would be a landmine akin to wiretapping the private conversations of couples magnified immensely, if they can't trust me (or whomever I'm paying to run the server at that point if a thousand compromised accounts is escaping my notice) to apply appropriate filters, they've already lost.
- We already take quiet note of who accesses Elliquiy via proxy or tor for detecting ban evasion.
- I already take action to prevent stagnant accounts from getting compromised when their e-mail is hijacked.
- I certainly know better than they do what regular behavior looks like. Especially on a roleplaying forum.
So they are either capable of telling me what they are looking for, or do not have a genuinely legitimate claim.