Comment spamming, which is an epidemic problem with WordPress blogs, has gotten to be a major issue with Movable Type as well.
Since inbound links are supposed to increase a site's popularity, some low-lifes have discovered that if they flood blog site commenting with hundreds of links, their own popularity rises. Online gambling sites are especially guilty of this tactic.
It has gotten so bad with many MT sites that the blogmasters have had no choice but to disable their commenting.
"Over the past two weeks, five hosts have in some way disabled MT or MT comments because of the server load they were creating," writes MT blogger Reid Stott. "Not five little Mom & Pop hosts - at least three of them I’d consider serious to top-notch hosts." Other bloggers also reported web hosts disabling MT scripts. One said their host, XO Communications, disabled MT after seeing 100 active connections to mt-comments.cgi, suspecting a denial of service attack was underway. Netcraft