If you are using the Technorati Link Cosmos using PHP then links that this tag generates will be counted by Search engines as being valid – which they may well be. But if a spammer sets up a blog, and links to you, you will be counted as providing a valid link. You might not want that to happen.
The altered script can be grabbed here: http://www.tamba2.org.uk/downloads/cosmos.phps
It won’t remove the link and it’s not ideal as you are tarring all links with the same brush, but it will make the spammers link useless for pagerank purposes.