More concerns about Ajax programming as a security risk
I previously inquired about whether Ajax programming would pose an increased risk for web apps to become compromised or rendered inoperable due to DOS attacks. I found a link from JamesDam.com about Ajax, and the author (James, assumedly) noted that one of the downsides of his web-based login sample using Ajax was that it increases the opportunity for a brute-force attack.
Also, Alex Russell notes Ajax's apparent flaw of a malicious user being able to "hammer Web 1.0 architectures".
There's also been considerable debate about security concerns about Ajax, after various Earle Castledine blog posts about using the JavaScript XmlHttpRequest object to spy on a user.