Lenovo Group Limited may be one of the largest computer manufacturers in the world, but several countries are worried about the Chinese technology firm's vulnerabilities to hacking. Intelligence and defense agencies in Australia, Britain, Canada, New Zealand and the U.S. have all banned Lenovo equipment from their networks.

The countries began scrutinizing Lenovo's technology in 2005 when the Beijing-based company acquired IBM’s personal computer business, and discovered problems with Lenovo hardware and firmware that allowed for backdoor access to hackers. Further tests concluded that Lenovo technology could allow hackers to remotely access devices without the knowledge of the owner. These backdoors are reportedly very difficult to detect.

In 2006, the U.S. State Department said it would not use 16,000 Lenovo computers on its classified networks because of security concerns. The U.K. and Australia introduced similar bans that have now been confirmed.

Lenovo said it is surprised by the ban and denied any fault in its machines, according to The Independent.

Last week, The Guardian reported that another Chinese tech company, Huawei, was under scrutiny about its connection with the Chinese government. It was recently reported that Huawei runs TalkTalk’s “HomeSafe” program, an Internet filter praised by Prime Minister David Cameron when he introduced his plan to require ISPs to introduce default porn filters. Huawei has repeatedly denied that that it works with the Chinese state.

Lenovo products are still allowed for use by other government agencies, just not for networks handling sensitive material. Without specific proof given, it is hard to tell if these criticisms of Chinese companies are warranted or just the result of anti-Chinese bias.

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