Recommended reading: Weapons of Math Destruction: How Big Data Increases Inequality and Threatens Democracy, by Cathy O'Neil. This eye-opening book is about what the author calls "the dark side of Big Data"--how algorithms are used in sinister or negligent ways, in matters ranging from mortgage lending to for-profit prisons. It may be uncomfortable reading for people (like me) who love math, but as O'Neil puts it "math deserves much better [than to be used in such ways] and democracy does too."
Some related things to read: Edward Frenkel's great book Love and Math: The Heart of Hidden Reality, which though it is essentially a love letter to his subject, opens with a warning about how math can be misused, by Wall Street and others. I interviewed Frenkel about that and related matters for my former employer Research magazine.
Thinking back, I've been edging into such topics for a long time. I recall writing an article for U.S. Banker magazine in the early '90s about how data mining was becoming an important new technique in the financial industry. The banks were claiming it would help them have "relationships" with their clients, a claim for which I think I had some skepticism (but the article doesn't seem to be online). I also wrote around that time about how financial "rocket scientists" were using derivatives, in a piece for Insight magazine (also not online, at least not for free), but true to my conservative allegiances of the time, regrettably, I downplayed the potential problems.
Finally, I recommend reading this: "Revealed: how US billionaire helped to back Brexit," by Carole Cadwalladr in The Guardian. The billionaire is Robert Mercer, who played a key role in Trump's rise to power. Mercer will be remembered as a man who used data to damage democracy, in the U.S. and Britain. That damage can only be limited by more people knowing the math and computer science that's being used to undermine our freedom.