It is amazing how much spam wafts around. Just what is the object of comment spam, I have to wonder. (See Wikipedia’s take on it below.) I suppose it is getting someone else to host links to your web site to increase traffic and improve the spammer’s Google rating by having more links on other sites. That would be cheating!
Thankfully there are good guys who find ways to ward off the cheaters. I found a plugin named in the title that claims to catch all machine made spam. Sounds great and I look forward to not seeing leaches trying to attach themselves to my blog and wasting my time deleting them. The plugin is by Todd Lahman and he sounds quite confident that it works. It adds a password and a field to paste the password into to verify the comment is from a human. Hope it works! It is a little more of a hassle for the person commenting but tolerable and not as bad a trying to type in letters and numbers that are nearly unrecognizable as used by many forms.
Here is a quote from Wikipedia on blog spam.
Blog, wiki, and guestbook
Blog spam, or “blam” for short, is spamming on weblogs. In 2003, this type of spam took advantage of the open nature of comments in the blogging software Movable Type by repeatedly placing comments to various blog posts that provided nothing more than a link to the spammer’s commercial web site. Similar attacks are often performed against wikis and guestbooks, both of which accept user contributions. Another possible form of spam in blogs is the spamming of a certain tag on websites such as Tumblr. On March 18, the ‘Hipster’ and ‘YOLO’ tag on Tumblr was spammed by photos of Paul McCartney, due to the dedication of a number of Beatlemaniacs and their persistent posting. Those searching these tags would have been confused to see the pictures of Sir Paul, lord of the Hipsters.