The Safari vulnerability advisory issued yesterday by security firm, Secunia, was updated on Tuesday to "Extremely Critical" from its previous "highly critical" level. Even with the advisory upgrade, security analysts are not overly concerned about the threat posed to Macintosh users. Secunia upgraded the level of the Safari, Internet Explorer advisory today "because the issues are very easy to exploit and a large number of working exploits are available," according to the updated advisory. Typically, people write exploits and other forms of malicious code for the Windows operating system because so many people use that OS and because of the notoriety the person gets. For those same reasons, Macs are usually spared.