网络上正在发生一场黑客混战， Facebook 和Twitter被夹在中间。

　　匿名黑客12月8日对那些被认为对维基解密网站造成伤害的公司发动了攻击，试图阻止用户访问这些公司的网站和服务。万事达卡、维萨卡、PayPal公司在维基解密网站发布机密外交电报后，切断了人们通过它们向维基解密网站捐款的渠道。

　　为了组织活动，黑客们使用了诸如 Facebook 和Twitter这样的网站。他们的这一行动使网络巨人们被卷入混战，使它们感到不安。

　　Facebook和Twitter，尤其是Twitter最近几年因为成了言论自由的载体而获得称赞。那些试图控制消息流的政府发现它们很难阻止人们通过这些网站自由发表言论。与此同时，Facebook和Twitter都有公司愿景，这些愿景的实现取决于它们为其它公司充当广告平台的能力。这使它们在如何处理政治性如此强的维基解密网站事件时面临棘手的公共关系和商业决策。

　　一些互联网专家称，这一情况突显了互联网上言论自由议题的复杂性。从基层起家的网络公司在此期间不断演变，它们对用户能够公开发言的内容部分拥有核心控制力。研究互联网并在纽约大学任教的克莱-舍基称，尽管网络是一个新的公共领域，它事实上是“一个容忍公开言论的公司领地。”

　　“电子疆界基金会”的律师玛西亚-霍夫曼称：“那些关心言论自由或者要发表有争议或者不受欢迎信息的互联网用户应当感到担心，事实是网络公司中介可以不让他们发表那些信息。你的言论自由权利只与那些弱小的中介相当。”

　　轻变传奇私服 Give Web Companies a Test of Free Speech

　　A hacking free-for-all has exploded on the Web, and Facebook and Twitter are stuck in the middle。

　　On Wednesday, anonymous hackers took aim at companies perceived to have harmed WikiLeaks after its release of a flood of confidential diplomatic documents. MasterCard, Visa and PayPal, which had cut off people’s ability to donate money to WikiLeaks, were hit by attacks that tried to block access to the companies’ Web sites and services。

　　To organize their efforts, the hackers have turned to sites like Facebook and Twitter. That has drawn these Web giants into the fray and created a precarious situation for them。

　　Both Facebook and Twitter — but particularly Twitter — have received praise in recent years as outlets for free speech. Governments trying to control the flow of information have found it difficult to block people from voicing their concerns or setting up meetings through the sites。

　　At the same time, both Facebook and Twitter have corporate aspirations that hinge on their ability to serve as ad platforms for other companies. This leaves them with tough public relations and business decisions around how they should handle situations as politically charged as the WikiLeaks developments。

　　Some internet experts say the situation highlights the complexities of free speech issues on the Internet, as grassroots Web companies evolve and take central control over what their users can make public. Clay Shirky, who studies the Internet and teaches at New York University, said that although the Web is the new public sphere, it is actually “a corporate sphere that tolerates public speech。”

　　Marcia Hofmann, a lawyer at the Electronic Frontier Foundation, said, “Any Internet user who cares about free speech or has a controversial or unpopular message should be concerned about the fact that intermediaries might not let them express it。”

　　She added, “Your free speech rights are only as strong as the weakest intermediary。”

　　The problem came into relief on Wednesday, through an effort called Operation Payback, organized by a group calling itself Anonymous. The group spent much of the day posting notes on Facebook and Twitter that told followers which companies to single out and that documented hacking successes。

　　But Facebook banned one of the group’s pages, saying that using the site to organize hacking attacks like that violated its terms of use. The group went on Twitter to complain。

　　A Facebook spokesman issued a statement saying that the company was “sensitive to content that includes pornography, bullying, hate speech, and threats of violence” and would “take action on content that we find or that’s reported to us that promotes unlawful activity。”

　　In an interview Wednesday morning, Joe Sullivan, Facebook’s chief security officer, addressed WikiLeaks’s own presence on the site. He said the company had not received any official requests to disable pages or accounts associated with the WikiLeaks organization。

　　Facebook generally resists requests by governments or advocacy groups to take down material if that content is not illegal or does not violate Facebook’s terms of service, which prohibit attacks on individuals or incitements to violence。

　　“Facebook is a place where people come to talk about all sorts of things, including controversial topics,” Mr. Sullivan said. It was not clear whether anyone had asked Facebook to take down the Operation Payback page。

　　Twitter allowed the Operation Payback account to stay active most of Wednesday. But the group’s account was disabled late in the day, after it posted a link to a file that provided thousands of consumer credit card numbers, according to a person with direct knowledge of the situation。

　　A Twitter spokesman declined to discuss the details of the situation. “We don’t comment about the specific actions we take around user accounts,” he said。

　　The company is not overly concerned about hackers’ attacking Twitter’s site, he said, explaining that it faces security issues all the time and has technology to deal with the situation。