Tom Keating has an interesting post today documenting his discovery that Microsoft Vista is not currently letting the Alexa toolbar pass through it’s security defenses. Apparently Vista’s Defender program classifies Alexa as a Trojan program and assigns a High risk level to the software. I have to agree with Tom that Alexa seems like an unusual program to treat as malware.

This does bring up a recurring question I have had about Alexa, though. Alexa data is widely cited as one of the more accurate overall traffic measurements available on the net, and I have always been skeptical of that. I don’t run the Alexa toolbar on any of my browsers, nor do I know anyone who does. Am I missing something in how they get their data or why it should be considered as authoritative as it often is? I’m curious, do you use Alexa data or have the toolbar installed, or have any thoughts on how accurate the Alexa traffic data is? If so, please drop a note in the comments section, I’d love to hear from you.