Deleting the contents is illegal, heck, even accessing the server is illegal. Furthermore, it destroys evidence the ISP needs to shut it down.

That's why I hoped it was code. He wouldn't want to acknowledge illegal activity on his blog; though technically logging into the FTP server is probably illegal in itself.

depends I didn't see any banner and one could argue that his posting was covered by hue and cry :-)

"In common law, a hue and cry is a process by which bystanders are summoned to assist in the apprehension of a criminal who has been witnessed in the act of committing a crime."

Or, change the FTP password and email that to the ISP abuse team. Spammer is locked out.

How are you going to change an FTP password from an FTP client?

Good point. Meh. Assume it's also root pass for SSH on that box?