Panic is spreading among file-sharing web sites with a US user base, with FileSonic, FileServe and Uploaded.to all restricting their services following the shutdown of Megaupload last week.
"All sharing functionality on FileSonic is now disabled," says a message on the FileSonic homepage.
"Our service can only be used to upload and retrieve files that you have uploaded personally."
Uploaded.to and FileServe carry no messages on their homepages but FileServe is said to be taking similar action to FileSonic, while Uploaded.to reportedly suspended service to US customers.
V3 contacted FileServe, Uploaded.to and FileSonic to ask for more details on the service closures, but has yet to receive a response.
The file-sharing websites allow users to share movies, games and software, but they all claim to stand against copyright infringement.
Last month, FileSonic teamed up with content identification provider Vobile to check all customers' files for copyright infringement before they are uploaded to the site.
The firm also tells its customers to send claims of copyright infringement to its designated copyright agent.
Elsewhere Rapidshare, one of the largest file-sharing sites in the world, does not appear to be making any adjustments to its service in response to Megaupload's closure.
Megaupload was one of largest online file-sharing sites in the world, with an average of 50 million visitors a day, accounting for four per cent of global internet traffic.
The site was closed last week and its founders, many of whom are based in New Zealand, have been charged by the US government with violating piracy laws, allegedly leading to $500m (£320m) in lost revenue for copyright holders.
The site can no longer be accessed, with its domain name seized and its homepage carrying an anti-piracy warning from the US Department of Justice and the Federal Bureau of Investigation.
The Megaupload founders are yet to stand trial and are currently under arrest in Europe and New Zealand, as the US requests their extradition. A Slovakian national, Julius Bencko, is still being sought.
The Megaupload site was based in Hong Kong, but the US indictment said it has jurisdiction, as some of the firm's servers were hosted in the US.
Hacktivist group Anonymous briefly took down the website of the US Department of Justice (DoJ) on Thursday, following the shutdown of Megaupload.
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