Short version: a survivor of online molestation, Katie Tarbox, wrote a book about her experiences, which was published by Penguin under the title Katie.com. Except that katie.com was the personal site of a totally unconnected person, Katie Jones, who used it for business and personal purposes, including putting up pictures of her young son. Jones first found herself flooded with unwanted emails about molestation; and was then bullied by Penguin's lawyers to "donate" her domain name to them. She refused, but the site became effectively unusable. The case got a lot of online publicity at the time, with Neil Gaiman amongst others weighing in on Jones's behalf.
According to this interview with Jones, Penguin had originally wanted to call the book Girl.com, but changed their mind when they found that that was the name of a porn site.
Well, I just went to Katie.com out of curiosity - and hey, it too is now a porn site.
Good job, Penguin.