Originally Posted by ebay.com user agreement

7. Access and Interference.
The Site contains robot exclusion headers. Much of the information on the Site is updated on a real time basis and is proprietary or is licensed to eBay by our users or third parties. You agree that you will not use any robot, spider, scraper or other automated means to access the Site for any purpose without our express written permission. Additionally, you agree that you will not: (i) take any action that imposes, or may impose in our sole discretion an unreasonable or disproportionately large load on our infrastructure; (ii) copy, reproduce, modify, create derivative works from, distribute or publicly display any content (except for Your Information) from the Site without the prior expressed written permission of eBay and the appropriate third party, as applicable; (iii) interfere or attempt to interfere with the proper working of the Site or any activities conducted on the Site; or (iv) bypass our robot exclusion headers or other measures we may use to prevent or restrict access to the Site.