A new column the Wall Street Journal argues that companies like Google, Facebook, and Amazon are heading towards monopoly status in their respective industries.

A Thursday column in the Wall Street Journal by Christopher Mims argues that several Silicon Valley giants are gaining monopoly-sized market shares in their respective industries. Mims explained that modern monopolies look much different than monopolies of the past. Mims cited the example of monopolist Andrew Carnegie using armed guards against his striking workers.

One way today’s monopolists are different from the robber barons of old is that they’re not exactly ​behaving like, for example, Andrew Carnegie, who turned armed guards on striking workers. And regulators don’t particularly care if a company is a monopoly unless it harms the public or hampers innovation. But on those counts, many argue we’re close. Take the way both Google and Facebook dominate the harvesting of user data, or Facebook’s ethically dubious decision to release vast quantities of personal information to developers.

According to the column, Google and Facebook take in a vast majority of U.S. digital advertising. Amazon accounts for a whopping 44 percent of e-commerce sales.