A large group of protesters gathered outside the Boston Harbor Hotel Wednesday as Freddie Mac CEO Ed Haldeman Jr. gave the keynote speech at an exclusive luncheon held by the Boston College Chief Executives' Club. Haldeman was invited to discuss the role of Freddie Mac, the government-run mortgage financing firm which he serves as chief executive, in the collapse of the housing market as well as its role in the recovery.Hotel employees had to draw the curtains in the hotel's outside in order to block the attendees' view of the protesters, mostly from the Boston-based activist group City Life, or Vida Urbana. Haldeman said in an interview that he understands the protesters' complaints. The protesters, who had also staged a rally in front of the Financial District offices of Fannie Mae, were mainly criticizing a policy prohibiting rental of foreclosed properties to their former owners.City Life is a Jamaican Plain organization that was founded to fight for tenants' rights and affordable housing for lower-class city residents. Earlier in the day, Freddie had announced that Haldeman would be stepping down as the agency's CEO after two years on the job. He will, however, stay on as the agency searches for his replacement.