It is my understanding that recent changes to European law regarding your "right to be forgotten" allow you to right to redact results on searches of your name . According to news reports, this right went into effect immediately upon the passage of the law and applies to all search engines. it may not affect the actual blog post, but it can affect someone's ability to find the blog post if they use a search engine to try to find it or search for general info about you. I strongly suggest you consult with a barrister in your area about this new Right to be Forgotten.
Defamation laws vary from one jurisdiction to another, and they change from time to time. I believe defamtion laws in the U.K. were recently amended to make it harder to sue for defamation there. What is consistant everywhere is that defamation cases are hard to win and very expensive to prosecute.
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There are two approaches to your problem. The first is litigation, which is long, vexatious, expensive and uncertain. The second is to learn and apply Wordpress's terms of service to your advantage.
I leave the choice to you, but despite the "right to be forgotten" ruling in Spanish Courts against google, the enforcement of such claims on a US entity could likely take years. By the time you won your case, you would have publicized the blog more than you would like, and any damage to your reputation would have multiplied exponentially. The choice is yours, but I think you can see that the latter seems to make more sense than the former.
One additional venue that you might consider pursuing is criminal complaint against the author of the blog for publication of such falsehoods. Beware of this option, however, because opening a criminal complaint in what may be a he said/she said involving what you believe to have been consensual could have very messy implications and potential criminal outcomes for you.
Best of luck.
This does not constitute legal advice or the engagement of my services as an attorney.
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