Currently there's a major privacy concern when running vanilla Jenkins. It comes with submitting anonymous usage statistics to jenkins-ci.org enabled by default. It's not even disclosed to the user that it is happening.

Incorrectly categorized setting

In 1.x versions of Jenkins, the setting to disable submitting anonymous usage statistics was grouped with Maven settings. This made it even less obvious that it was even recording and "phoning home" to jenkins-ci.org.

Enabled by default

It continues to be enabled by default in Jenkins 2.x. The user/admin is not notified this in any way.

Improvement

I think it would be great if the setup wizard in Jenkins 2.0 gave the user/admin the opportunity to know the setting is enabled. I would at least like this disclosed in the wizard and where to change it. I'll leave it up to the developer to decide if it should be able to be disabled in the wizard or how it should be disclosed.