Ubuntu adds features in ways that we find dangerous for privacy. For an example, see [EFF: Privacy in Ubuntu 12.10, Amazon Ads and Data Leaks](https://www.eff.org/deeplinks/2012/10/privacy-ubuntu-1210-amazon-ads-and-data-leaks).
Our team sometimes publishes emergency releases, whenever important security upgrades are available in Debian or *Tor Browser* before the next scheduled release.