LOS ANGELES (Reuters) - A popular sex classified website said this week that it was shutting down its services in the United States, citing the likelihood that legal challenges would fail to overturn a landmark package of federal sex trafficking laws passed by Congress a year ago.

FILE PHOTO: U.S. President Donald Trump signs H.R. 1865 "The Allow States and Victims To Fight Online Sex Trafficking Act" at the White House in Washington, U.S., April 11, 2018. REUTERS/Kevin Lamarque

The decision by MassageRepublic.com marks the latest indication that the Stop Enabling Sex Traffickers Act and Fight Online Sex Trafficking Act, known collectively as FOSTA-SESTA, has made it difficult for websites selling sex to survive in a climate of higher risk for them.

“When one of these sites shuts down it usually inspires others to shut down,” said Rob Spectre, chief executive of the counter-human trafficking technology company Childsafe.AI. “It’s another signal of the volatility in this market - there are going to be some wild swings ahead this year.”

President Donald Trump signed the bipartisan FOSTA-SESTA into law just days after federal law enforcement officials seized Backpage.com, at the time the dominant player in the internet prostitution market, in a U.S. Justice Department sex trafficking and child prostitution investigation.

Seven people, including the website’s founders, were charged in a 93-count indictment with facilitating prostitution, money laundering and fraud. Backpage CEO Carl Ferrer pleaded guilty to state and federal charges, agreeing to cooperate in the case and shut down the website.

“In the current environment, we are not sure that the challenges ... to this dumb law will succeed, so have no choice but to suspend service,” the owners of MassageRepublic.com wrote in a blog post explaining the decision.

“Since FOSTA/SESTA, this site has not billed a single dollar to any advertiser or user, nor has received any other financial income or benefit based on any activity in the US,” MassageRepublic wrote.

MassageRepublic did not immediately respond to an interview request.

Experts say the crackdown has made it much more difficult for men who want to buy sex on the internet.

Sex worker advocates have fiercely criticized FOSTA-SESTA and have argued that taking down Backpage and similar sites would drive prostitution further underground or into the streets. Free speech activists say the laws unconstitutionally burden website owners with policing content.

MassageRepublic argued in its blog post that the main justification for the new law was child exploitation and human trafficking,” not purchasing sex services over the internet. “We have processes in place to identify this type of behavior, stop listings of that type and never got a complaint for the U.S. about anything like this,” it wrote.