Don't cast your hairy eyeball only at standalone PCs. One e-mail admin told me he once flagged an open relay that turned out to be an electron microscope at a Belgian university. HP printers have been used as zero-day warez (pirated software) FTP servers. The more gizmos that are connected to the Internet, the greater the possible venues for spam and viruses. (Doesn't that thought just brighten your day?)

8. If you do land on a blacklist, threaten to sue and make angry demands.

It is possible to find your site on a blacklist because of an innocent mistake. But when you go to resolve the situation, assume that it was your error or ignorance that caused the problem, not someone else's fault. Do not threaten. You may find yourself on the "permanent block list" with no chance to be removed. One e-mail admin says he blacklists for life anyone who tries to sue, including legal firms handling the cases. "Since they support Internet abuse, they really don't need to have the privilege of using it," he adds.

Matthias Leisi, project leader at dnswl.org, a "whitelist" of known legitimate e-mail servers, says, "We once had a guy threatening to sue us at dnswl.org if we would not immediately list all his IP addresses with highest trust score. When we told him that this is not the way we operate, he went into ALL CAPS MODE, telling us what a bunch of incompetent losers we are, and that he still insists to be listed, "or else...".

In point of fact, there is no "or else." Like a baseball player who disagrees with an umpire: the umpire may be wrong, but his decision is final. If you argue, you'll just be thrown out of the game.