The possible reasons for this are: You attempted to crawl spider the site. This may include the use of so called "site download" software.
Please note that crawling of this site is prohibited. Somebody else from the same network or ISP Internet Service Provider has crawled the site and was blocked as the result.
This may have nothing to do with your use of our website or your software. We apologize for the inconvenience.
Persistent errors? We would like to hear from you.
Please submit as many details as possible on how to reproduce the problem you are having. Report the problem.