DoS Protection Service for Java - Google App Engine - Google Code（情報元のブックマーク数）
Google App EngineにDoSプロテクションとしてIPベースのブラックリストが設定できるようになったそうです。（気休め・・・
http://code.google.com/intl/en/appengine/docs/java/config/dos.htmlDoS Protection Service for Java
The App Engine Denial of Service (DoS) Protection Service enables you to protect your application from running out of quota when subjected to denial of service attacks or similar forms of abuse. You can blacklist IP addresses or subnets, and requests routed from those addresses or subnets will be dropped before your application code is called. No resource allocations, billed or otherwise, are consumed for these requests.
Do not use this service for security. It is designed for quantitative abuse prevention, such as preventing DoS attacks, only. Some requests from blacklisted users may still get through to your application.
