Three out of four Americans are concerned about internet and computer security, according to a recent poll.

A national survey by the Information Technology Association of America (ITAA) and managed secure communications specialist Tumbleweed Communications, found that 74 per cent of respondents feared that personal information could be stolen or used for malicious purposes.

The poll, entitled Keeping the Faith: Government, Information Security and Homeland Cyber Defense, was based on a survey of 800 adults conducted on 26 and 27 November.

Three quarters of the respondents expressed worries about terrorists using the internet to launch cyber attacks against critical infrastructure but the poll found that, despite these fears, respondents failed to register major changes in online behaviour as a result of the 11 September attacks or the subsequent war on terror.

Interestingly only 17 per cent said they had complete faith in the ability of the US government to prevent cyber attacks against agencies; 54 per cent said they had some faith, and 17 per cent said they had very little faith.

ITAA spokesman Bob Cohen said that the group was surprised by the level of concern that respondents expressed about attacks on critical infrastructure.

"We think it's notable that the public retains confidence that the federal government will be able to assure the security of its information systems, and [that the public] does not appear to be particularly troubled by the possibility of unwarranted government surveillance," he said.

Few people in the survey claimed that they were concerned that, in the environment after 11 September, their email would be subjected to government scrutiny.

Only 10 per cent said they were a lot more concerned about federal authorities monitoring or reading their email, while 14 per cent said they were somewhat more concerned.

Even with the Anthrax events, email has not become a replacement for paper mail. Some 55 per cent said their use of email had not changed, while 35 per cent said they did not use email at all. Only three per cent said they had made a significant shift to email to avoid paper mail.