A journalist waives the protection provided for confidential sources and information under the reporters’ privilege "if the journalist voluntarily discloses or consents to disclosure of the protected information." 16 M.R.S.A. § 61(4). No Maine cases discuss waiver of a journalistic privilege or protection for non-confidential sources or information, though clearly public disclosure would weigh heavily in ordering disclosure by subpoena. The same would apply to a partial disclosure to a lesser degree.
In Maine generally, a party or nonparty that may assert a privilege, confidentiality protection under the shield statute, or privacy protection may waive the right to hearing and any applicable privileges or protections by notifying the court in writing that they intend to do so. Me. R. Crim. P. 17(d) (attendance of witnesses); Me. R. Crim. P. 17A(f) (documentary evidence or tangible objects).