The equations of big-data algorithms have permeated almost every aspect of our lives. A massive industry has grown up to comb and combine huge data sets — documenting, for example, Internet habits — to generate profiles of individuals. These often target advertising, but also inform decisions on credit, insurance and more. They help to control the news or adverts we see, and whether we get hired or fired. They can determine whether surveillance and law-enforcement agencies flag us as likely activists or dissidents — or potential security or criminal threats….Largely absent from the widespread use of such algorithms are the rules and safeguards that govern almost every other aspect of life in a democracy. There is an asymmetry in algorithmic power and accountability…Fortunately, a strong movement for greater algorithmic accountability is now under way. Researchers hope to find ways to audit for bias….Society needs to discuss in earnest how to rid software and machines of human bugs.