AJAX - good or evil

The below article covers interesting point about AJAX...

Consider this example,
1) You are filling some bank's loan form..In the middle u get a call from yr friend saying don't apply loan in that bank..And yr friend suggests some other bank name....In that case you are closing that page without pressing the submit button...But if that page uses AJAX, your information have been updated their database and u can get a call at anytime from that bank ..

2) You are visiting one website...u r doing nothing in that page..not even clicked any single link...But you know , if that site uses AJAX, yr mouse move attributes and the time spent on that page, have been stored in their database..

like this we can say more examples.....But still I consider AJAX is the next revolution in the web..

checkout this link for more details....AJAX to Spy On You