Travel, webmail, and social networking sites are more commonly blocked by businesses than gambling and adult content sites.

A survey of 300 security pros by security firm Webroot found that workers frequently visit travel, webmail, and social networking websites while attempts to surf smut or gambling sites are less common. Users are effectively policing themselves, the survey revealed.

For example, social networks have been identified as a new vehicle for spammers – with "spamverts" targeting users of social networking sites by promoting links to sites that contain malware.

Webroot warns that firms that allow open access to social networks are effectively providing a loophole that spammers are able to exploit in phishing attacks. In particular, various "Wall" applications, which allow users to post and propagate text and multimedia content, are being abused as a conduit for junk by spammers.

In some cases, links to user profiles are being subverted, redirecting users to credential-snaffling websites. ®

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