By today - if not before - it was clear that a new way of getting sources has evolved in addition to the classic combination of detective work and/or hoping for a “walk-in” tipster to contact the journalist: crowdsourcing.  
   In crowdsourcing, either the journalist throws out on social media an idea of what he wants and hopes somebody, anybody, replies with information that can be verified fast - or people for whatever reason of their own use online forums that the journalist has access to in order to piece together the skeletal details that can enable the journalist to flesh the story out.  The second type of crowdsourcing is especially possible if the subject of the story is hated by a large group of others.
   An example of that independent type of crowdsourcing - which again made the news today as the Raleigh, N.C. News & Observer detailed how its series unraveling a sports scandal at the University of North Carolina came about.  Whether or not today’s story mentions it in detail, its start was in independent crowdsourcing - by alumni of UNC’s archrival, nearby N.C. State Univ. on an online forum for State’s sports fans as people using code names such as “WoofWoof2” (State’s teams are called the Wolfpack) in turn independently used Google etc. to find that the term papers of UNC’s football or men’s-basketball players were obviously plagiarized.  The Raleigh News & Observer - Raleigh being where State is located and the daily paper for where UNC is in a nearby county - then picked it up, leading to NCAA disciplinary action against UNC and probation from UNC’s accreditation agency.
   Also today, another top N.C. daily had a Facebook request made by one of its editors - for any information anyone could give regarding a story she was planning - as an example of that other form of crowdsourcing: the journalist-initiated kind.
   Of course, one disadvantage of crowdsourcing is that your competitors may well also pick up the story!  So - unless it’s a strictly-local story - asking for replies to be by email or direct message is best!