Civil asset foreiture as well as eminent domain follow a legal process with appeals routes and so on.
Not true. The cops can pull you over and help themselves to you cash. There is no "legal process" involved whatsoever.
Sure there is! What the cops do is legal, and here's the process:
1) Stop motorist.
2) Take motorist's cash.
3) Profit!
Although I think the "legal process" the GP was referring to was the basic justification for forfeiture spelled out in law, and the appeals process you can go through after the seizure to reclaim your property. Now, the law is certainly abused, but there's something the cops can point to and claim "we're doing that." Not so with impersonating someone else on Facebook.
I wonder, could you charge the agent under the CFAA? Clearly, he's exceeding the level of access to a computer system to which he's authorized.