A journalist is a person who collects, writes, photographs, processes, edits or comments on news or other topical information to the public I'm not certain a person simply dumping un-redacted data online is a journalist. They are a whistleblower.
A journalist will report with care and have ethical standards which they need to work within. They also have editorial guidelines and create new reporting based on the information they see. They make sure they don't endanger the lives of the people they are reporting on, particularly people in a war zone.
Whistleblowers are essential for democracy, but this guy crossed a line when he exposed people to danger. He also crossed a line when he took information from Russian spies, working for an autocratic leader, publishing it to interfere in another country's election. He has shown himself to be a puppet of autocratic leaders. He has no ethics or principles.
