I've seen lots of blogs on bcuk that have been defaced by trackback spammers. if you have trackbacks turned on, I suggest you turn them off in >Settings > Publishing tab, then scroll down and disallow trackbacks.

Its a shame that bcuk doesn't have an option to allow trackbacks from friends only, as that would be a better option.

If a spammer leaves a comment on your blog then you really must delete it, if you don't then you simply encourge them to do it over and over again.

Links are a form of currency on the web. They help drive search results. If you leave spam comments on your blog then some anonymous rude arsehole is profiting from your work. Do you want that?