First, you just have to be trustworthy.
Secondly, it is possible to have site visitors create their own E-mail address, just not easy. All new E-mail addresses have to be created through the panel, but it is possible to create a script to do this. Basically that script will have to log into the panel, and submit the information as if you were doing it.
There have been some other posts on the forum about this, and I'm sure there's some help in the wiki. It's possible, but would require an advanced coder.
art.googlies.net - personal website