Micheál Martin joined the video-sharing platform TikTok last month and got a swift reminder of the perils of social media. One of the Taoiseach’s first videos featured a picture of a huge Cork mural of a man with a cardboard box over his head. It was deleted after street artist Asbestos said he owned the copyright to the photograph and complained it was used without permission. Martin apologised. Another of the Taoiseach’s early videos was posted days after Fianna Fáil’s annual party shindig, featuring footage from the event. “How did our 80th Ard Fheis go?” the handlers of Martin’s account…