A spammer, kook, and/or troll who appeared on Usenet circa 1997 advertising a wide variety of sex toys. Chief among Mr. or Ms. Foo's offerings were butt plugs, which s/he affectionately if clinically referred to as "anal dildos".

Dildy Foo remains memorable not only for his/her impressive choice of handle, but also for the schtick s/he used when netizens suggested that spamming was not okay. Several times, in response to criticism of his/her business practices, Dildy suggested that the critics themselves clearly needed the advertised products, so as to help them escape sexual frustration. At one point, as I recall, s/he went so far as to offer to send free anal dildos to anti-spam activists in the hopes that they would find dilding themselves more amusing than protesting spam.

Today's spammers, sad to say, are not nearly as clever. Something is lost in society when crime itself becomes depersonalized.