When a friend told Hollie Toups that topless photos of her had been posted on an Internet pornography site, she felt horrified, but she didn't feel alone: She recognized more than a dozen other South Texas women on the website, she said.
Last Friday, Ms. Toups and 16 other women filed a civil lawsuit in Texas state court against the site, Texxxan.com, alleging that their intimate photos were posted illegally and included information that made them easy to identify. They are seeking damages and to have the site closed down.
Legal experts say they are seeing an increasing number of such lawsuits targeting so-called revenge porn, in which intimate images are posted online, often by jilted former lovers but also by computer repairmen or hackers who gain access to private photos. Some sites feature pornographic images alongside links to a subject's social-media accounts and other identifying information.
"I'm not saying I'm perfect, but I've been exploited," said Ms. Toups, a 32-year-old graduate student in criminal justice, who lives outside Houston. She said she had sent the photos years earlier to a former boyfriend, wasn't sure how they had ended up on the Internet, and hasn't sued the former boyfriend. She said the photos appeared on the website alongside a link to her Twitter account and clothed photos she had taken of herself and never distributed.
The administrator of Texxxan.com could not be located, and an email message sent to the site received no response. The suit also names GoDaddy.com as a defendant, claiming it hosts Texxxan.com. GoDaddy.com declined to comment on the suit.
The lead lawyer for the Texas plaintiffs, John Morgan of Beaumont, Texas, said he plans to sue the owners and operators of the porn site once he learns their identities.
"None of these women consented to having their photos used," Mr. Morgan said, adding that all of his clients subsequently suffered bouts of depression. "This site has to be shut down."
Finding the operators of porn sites can be difficult, as is persuading the police to investigate, legal experts said.
Federal law offers broad protection to sites that merely publish pornographic images taken by others.
"I wish we had more robust legal protection," said Danielle Citron, a University of Maryland law school professor who is working on a book about online harassment. She added that civil suits can be prohibitively expensive and victims often don't want further publicity by bringing litigation. "If you have to sue in your own name, the privacy invasion can be worse," she said.
Still, there are many legal options available to victims, according to lawyers across the country, who say people can sue for copyright infringement if they snapped the photos that later end up online without their consent.
Other potential claims include invasion of privacy and infliction of emotional distress, lawyers said.
"I have never even had to file a suit" to get porn sites shut down, said Kyle Bristow, a lawyer in Toledo, Ohio, adding that he has represented about a half-dozen clients, of both sexes, in such cases. "Just by putting people on notice that I'm coming after them has sufficed."
Erica Johnstone, a San Francisco lawyer who has represented about a half-dozen victims of revenge porn sites, said that "the emotional toll on women can be devastating," and includes depression and anxiety.
Ms. Toups said she at first became reclusive last summer, when she learned that her revealing photos had landed online. "I shut everyone off but my mom," she said, adding that when people greeted her in public, she wondered, "Is it because they are polite or have seen me topless?"
Texxxan.com, she said, allows subscribers to search for images of women according to regions of the state where they have lived. When she searched southeastern Texas, she found many other women she knew.
"I felt it was my duty to reach out to them and ask if they knew they were being harassed," Ms. Toups said.
A version of this article appeared January 23, 2013, on page A6 in the U.S. edition of The Wall Street Journal, with the headline: Women in Texas Suing a Porn Site.