LONDON - An offer by one of the world's biggest porn sites to stream its top service for free was condemned by critics as a move to exploit the coronavirus crisis and silence complaints that videos on its platform featured sex trafficking victims.Pornhub, a streaming platform for sexual content, has come under fire for allegedly failing to remove images and videos of child rape and sexual abuse on the site - claims it denies. An online petition to shut the site - which had over 42 billion visits in 2019 - now has over half a million signatures.As cities globally locked down this week to stop the spread of coronavirus, Pornhub said it would let users watch its top product for free for 30 days, with its traffic already rising 11.6% worldwide since the pandemic confined workers to home."Pornhub ... will offer Pornhub Premium to the entire world in an effort to encourage the importance of staying home and practicing social distancing during the COVID-19 pandemic," a Pornhub spokesman said in a statement.Data from the site showed a free trial offered to Europe before being offered globally this week had spurred a 57% spike in traffic from Italy, the worst hit European country for coronavirus, a 38% increase in France and 61% in Spain.Along with more clicks, however, have come renewed complaints about the video-sharing platform and questions about whether all the content available online is consensual.Pornhub, owned by Luxembourg-headquartered company MindGeek, denies allegations of knowingly running any content that is sexually abusive and rejects calls for tighter regulation."The measures we take make us far more regulated than any other major user generated platform," said a Pornhub spokesman."Any allegation that we aren’t taking this seriously is categorically false."He added that Pornhub denied as "categorically false" any suggestion there was evidence of sex trafficking on the site.Critics, however, have raised concerns the site is open to abuse and exploitation and increased traffic could exacerbate that."They’re making a lot more money and getting a lot more traffic," said Laila Mickelwait, director of religious anti-trafficking organization Exodus Cry, who posted the petition aimed at shutting down Pornhub."There’s going to be more exploitation, there’s going to be more demand, more users and then more videos uploaded to the site."The platform allows anyone with an account to post content. Content is then checked by human moderators and automated technologies.Women's rights experts have urged governments for tighter regulation to tackle abuse online and accused Pornhub of failing to act quickly enough to remove content when reported."It is therefore important for governments to put in place and implement strong laws that put a duty of care on tech platforms," said Tsitsi Matekaire, who runs an End Sex Trafficking program at women's rights group Equality Now.Internet Watch Foundation (IWF), which identifies and removes child sexual abuse imagery online, said it found 118 cases of child abuse on Pornhub from 2017-2019 but that this number was low and Pornhub quickly removed this content."Everyday sites that you and I might use as social networks or other communications tools, they pose more of an issue of child sexual abuse material than Pornhub does,” said IWF spokeswoman Emma Hardy.