The reddit Hyperloop team, which was formed immediately after SpaceX announced the competition, is now called rLoop. The team's original name was RedditLoop, which I imagine cased issues with reddit's legal department, for both trademark and liability reasons. The team's official new website is rloop.org. rLoop's next general team meeting is this Saturday, June 27, at 22:00 UTC.
Member of the rLoop team here, we did in fact change the team name proactively. Rather than waiting for any trademark trouble to arise, we just made the move before we had too much invested in the name.