If you have added your comment here somewhere, and it hasn’t shown up, it may be because you have left a very short comment that is just a little note, and a link to a site. That kind of comment tends to get snapped up by the spam filter, since it’s become a very popular way to inject dangerous links to blogs. Just write a comment like “hello there, nice blog” and then send it to 1,000,000 blogs automatically, with a link that leads the reader to a site that does cross-site, different injections, what have you. Not nice.
And it’s a bit much to check a lot of those links, and what if there’s a couple of sites using a security hole that’s still there? (The last sentence can be explained by telling, that, for example Firefox, every time someone reports a major flaw to Mozilla, they come up with a fix within hours rather than days. Usually the hole is not even publicized until Mozilla has had a day or two to assess how it affects their update schedule — now with Micro$oft you might be in trouble unless you really know you’re using the very latest and best from M$ — and the number of Internet Explorer 6s and 7s still in the ‘net is enough to make one understand how easy it is to create botnets…)