Apparently Google is at it again with the Google Web Accelerator. If you don't remember the GWA, it's the tool that prefetches requests on your behalf. Including links like "delete this", or "read this message", or "logout". Instead of resolving the problems in this version, it has made those problems even worse. All I can think is what the fuck? I know they don't want to be evil, but I just assumed that they also didn't want to be stupid...?
To all you who think that it's okay to vaguely obey some W3C spec, in the face of prevailing practice: you are wrong. Just absurdly and completely wrong. It's like being some obnoxious adult who stares in bafflement when a kid says "It ain't here", then responds "I don't understand you, did you mean 'it isn't here'?" Yeah, right; ain't is a word and we all know it. And GET isn't always safe, and we all know it. Pretending bafflement, as though you spend all your time reading the HTTP specs and no time using the web and noticing how the web works.
Quoting the W3C is doubly obnoxious, because they also produce the HTML spec, which they've sat on for years without providing conscientious developers the tools in HTML to do the Right Thing -- no nested forms, nothing that produces POST requests with anchor-like behavior, and generally no alternatives for generating POST requests except full-fledged forms and Javascript hacks. Nor have they provided the detail in HTTP to do the Right Thing in any case -- I still haven't seen any reasonable solution to the issue of tracking read mail: an operation that absolutely should be GET (and be accessed through link-like behavior), and yet also should have side effects (that the mail is marked as read). X-Moz: prefetch isn't in the HTTP standard (and apparently they've even stopped using that!)
I stand by my previous comments. You can tell Google what you think here.