Dan has one sibling: a younger brother. Yes, his name is widely known throughout the Phandom, but Dan has done an admirable job of never once saying it out loud, so we are going to follow his example here in the FAQ.
At various points in 2012 and 2013, he was harassed by Phandom members who discovered his Twitter and Tumblr accounts and then proceeded to bombard him with questions about Dan. This behavior prompted him to delete his account(s) on multiple occasions. The latest incident was on 9 February 2013.
Though you can find mentions of him in old radio shows and liveshows, Dan’s brother’s existence is now, understandably, a very sensitive topic. Dan is very protective of his privacy (the phrase, “Fuck off and don’t be a stalker” has been uttered), and mention of him within the Phandom is now largely avoided, to combat further harassment and invasion of privacy.
Dan's response to the incidents
At the time of the first major discovery of Dan's brother's social media, in August 2012, Dan made a series of tweets about the situation:
A month after the incident of February 2013, he addressed the issue quite bluntly in his 5 March 2013 liveshow:
"Can you discuss your brother?"
"Yes. Fuck off and don't be a stalker! ...I'm joking."
(but of course he's not actually joking )