“Why would it be unethical, any more than it is unethical to wear a highly visible company logo on a piece of clothing?”
My response is in the comments:
“Someone tell him to make highly visible red and pink stickers which say TEXAS HOLDEM POKER PHENTERMINE VIAGRA MILF RAPE SEX, then walk around Oslo, randomly slapping those stickers onto people’s clothing without permission, then claim that it’s all perfectly ethical when the mob comes with pitchforks and tazers.”
…Because that’s what referrer and weblog spam is more analogous to. Joe at Spam Chongqing has the shirt.
Update: This entry is now a regular target for revenge spam attacks, which is great, because each spam comes with a bunch of URLs and an IP, all data which help me build a distributed blacklist. At the same time, I regularly delete the spam after using the information supplied, so they get no search engine value out of it. (Not that they get anything anyway, since rel=nofollow has been implemented on my comments.) Just goes to show, spamming might make money, but money can’t buy morals. Or brains.