You are most propably here, because you have seen accesses from an user with the useragent "yacybot" in your webserver-logs.

What is yacybot?

"yacybot" is the useragent of the software YaCy, which is an approach to build a Peer-to-Peer based websearch-engine. "yacybot" is the useragent of the YaCy webcrawlers which are maintained by the YaCy users and work the same way as e.g. the googlebot.

How to control yacybot?

YaCy follows the rules defined in a robots.txt file.
If you do not wish that YaCy crawls your website, please set up such a file. It is the standard way to control all web-spiders like Google, Yahoo! and also YaCy. In case you don't know how to make such a file please read http://www.robotstxt.org/ for further instructions. After some hours all yacybots will obey your instructions.

This didn't help me.

If there are any questions left please visit our forum and ask for help.