![Joi Ito [logo]](/_site/img/joi-ito-logo-300.png){kind=logo}
Speaking of false positives, I'm also against blacklists because they can also cause false positives that are difficult to correct. Smartmobs was blacklisted by Verio and it took Roland two months of hell to get it sorted out.
I know I use a blacklist for my comment filtering. It's a stop-gap measure until someone figures out a better solution.
Yea, blacklists are a sledgehammer when a surgical approach is needed. I am an investor in Cloudmark and they are working on some interesting stuff in this area. Their approach to e-mail spam is already the highest effectiveness with lowest false positive.
Joi, as I pointed out in comments of the above linked post, blacklists that are centrally maintained and which cut off IP-level access completely are dangerous and, as Martin said, sledgehammers.
MT-Blacklist is neither of those. All of the MT-Blacklist blacklists are maintained by the end users and the only effect is that you can't use the specified string in a comment or trackback.
It's not like your email won't get delivered or you won't be able to view a site, as in the case of the person who wrote the blog entry that you linked to (which is horribly misnamed as I and about 20 other people pointed out).
MT-Blacklist is not only elegant and easy to use (for both site owners and site visitors), but it also isn't overkill. Let me know if the "stop-gap" measure causes you an problems, and I will point out how it should be correctly used.