safety on your computer
information on cookies.
cookies come not from the site you're visiting, but from advertising companies that manage the banner ads for a set of sites, these advertising companies can develop detailed profiles of the people who select ads across their customers' sites.
information on worms.
information on viruses
you can protect yourself the same way as protect yourself from online worms, install an antivirus software, use a firewall, do not open email attachments unless you know who its from and what it is and keep your computer updated.
information on spyware
to protect yourself, use a firewall