I've been getting an awful lot of spam comments lately. The format is always the same. A gushing compliment on the blog or specific post, often in mangled English and not in any way relevant to the post subject, followed by a link to the commenter's own web site.
Until recently my spam filter caught most of these but they are now creeping through, and the subject matter of their links is getting increasingly undesirable. I've just deleted one possibly connecting to an under age porn site.
Comments moderation is all I can do about this. Don't be put off if you wish to make a genuine comment. Those are (almost) invariably welcome.