More than 3,300 MIT alumni and friends returned to campus during Tech Reunions 2015, held June 4–7. Alumni enjoyed 160 events, including Tech Night at Pops, class dinners, and Technology Day lectures focused on the changing nature of online security and privacy. Alumni Association president Don Shobrys ’75 and the 50th-reunion class led the MIT commencement procession into Killian Court, where Megan Smith ’86, SM ’88, the chief technology officer of the United States, addressed the class. At the Technology Day luncheon, class leaders announced that reunion giving from all classes totaled more than $30 million.