I found an cronjob on www.osgeo.org hitting
http://2011.foss4g.org/cron.php every hour.
As that URL is a 404 now, I removed the line.
Shall anyone need it back, let me know.
Beside:
2011.foss4g.org has address 140.211.15.68
www.osgeo.org has address 140.211.15.66
--strk;