Besides turning off everything in Edit/Preferences/Advanced/Data Choices and browser.newtabpage.directory.ping
browser.newtabpage.directory.source
browser.safebrowsing...
security.ssl.errorReporting.enabled
What should one change in Firefox settings to avoid sending extra info to Mozilla?
telnet server.com 80
, followed byGET /some/page HTTP/1.0
and two carriage returns. Parse the html/javascript in your head and respond accordingly. This way you can be sure to only send the relevant data.</joke>