I don’t think a reporter should attempt to ‘friend’ someone on social media to get additional information from them. I don’t think a reporter should do this because if the reporter sees something like a post or something the person has shared, they could attempt to use that to add to their story.
One example of using information that wasn’t given willingly is an article by Helen Lewis, when she writes about how journalists are starting to face more and more ethical problems with reporting using data that was taken by leaks or hackers. Even though someone ‘friending’ a source might not be hacking or leaking information, they’re still using information that wasn’t provided to them by the person who they’re looking up on social media.
I think that if a reporter needs more information on a person, they should reach out to the person over email to interview them again or to gain more information that’s needed. This is probably more ethical because people put personal stuff on social media that they might not want people outside their friend group to know. I also think that if a reporter ‘friends’ someone, they might forget to unfriend them and have to write a story about them later on again and they might be bias depending on how much they interact on the social media.
Lewis, Helen. When Is it Ethical to Publish Stolen Data? Neiman Reports.