A WCVB-TV story about after-hours parties in Boston caused a kerfuffle this week. Reported by Channel 5’s Mike Beaudet and a handful of journalism students at Northeastern, where Beaudet teaches, the investigative piece revealed that parties are sometimes held in warehouses and other unapproved venues, and alcohol and drugs are often present. Some viewers objected to Beaudet sending his students to these underground affairs to get video of the late-night shenanigans, which was then used in the story. (In the video, people’s faces are digitized to obscure their identities.) Beaudet, who’s been trolled on Twitter and Facebook since the story aired, declined to talk to us Thursday. But his boss at Northeastern, Jonathan Kaufman, director of the School of Journalism, doesn’t see a problem. “This was the story the class decided was worth pursuing. Mike talked to them about how to approach it, and they went out reported it, talking to organizers of these parties and city officials,’’ said Kaufman. “None of us in the media do a good enough job reporting on what life is like for young people in the city. The response shows what a legitimate story it is.’’