By googling, I discovered that Edison Research has a near monopoly on providing real time election results to the media. Here is their website: http://www.edisonresearch.com/election-polling/. They write on their website "Edison Research is the exclusive provider of election exit polls to the National Election Pool consisting of ABC, CBS, CNN, FOX, NBC and the Associated Press." I was wondering who or what guarantees the accuracy of their reporting. To what extent are they immune from say Russian hackers? an employee with a grudge? Do the news outlets have any real time checks or balances on the information provided by Edison Research?
My understanding is largely based on reading the Edison Research website and this news article from 2012. It is possible that information can be found on a state by state basis. I'm not sure. There is for example this New York website which as of today (11/9/16) still insists its election results for the 2016 election are unofficial.