To understand digital advertising, study its algorithms

ALAN MISLOVE studies algorithms. Recently, his research at Northeastern University, in Boston, has shown that Facebook’s software was leaking users’ phone numbers to advertisers. He has also found new ways to audit that same software for racial bias. But work like his faces challenges. Scraping data from public-facing websites often sails close to breaching their terms and conditions. And the companies those websites belong to are generally unwilling to give researchers more direct access to their systems.