I don't think spoofing email addresses is a good idea. But people concerned with needlessly being dragged into controversy who have information that could guide DOJ towards real justice, such as the identity of people involved in the government's delivery of firearms to Mexican drug gangs, or civil rights violations like selective prosecution of Hispanic men, could use an email address which has a limited lifetime, like those available from www.guerrillamail.com or http://10minutemail.net/en/ to register a new email account with a public email provider like Yahoo, Mail.com, etc.
Note that your IP address would still be available to the NSA and other similar parties via the backdoors in most public web based mail services. So you should log on to that email service via a TOR network if you want maximum privacy, or use the public access wifi at a suitable location for enhanced, but not guaranteed privacy.