Claire Rousseau (not on Booklikes, but has a website: http://www.clairerousseau.com/ ) explains how to send a formal complaint to The Guardian. The letter she wrote is so perfectly worded, but plagiarism isn't cool so you'll have to write your own. (She grants permission to use portions of her complaint: "Feel free to use portions of my complaint if you’d like." Thank you!)
Claire Rousseau's complaint: http://clairesrousseau.tumblr.com/post/100660418843/this-is-the-complaint-i-sent-the-guardian-readers
Claire Rousseau's handy how-to complain guide: http://clairesrousseau.tumblr.com/post/100660951178/how-to-complain-to-the-guardian-about-the-hale-article
I found these links via the ever-informative Bibliodaze's Twitter account: https://twitter.com/Bibliodaze
Now, how to complain to HarperCollins/HarperTeen about their continued silence on the matter, which leads us to believe they condone their author's [stalking] actions...