Reuters reports we can add Verizon to the list of companies whose customers’ email addresses were obtained by a hacker in the recent Epsilon data breach. Meanwhile, CNet and the Wall Street Journal examine exactly what Epsilon and companies like it do and how much data about us they have. Epsilon and companies like it are filling a void for businesses like Target and Best Buy because taking care of the millions of emails that go out to millions of customers is really complicated.

From the Wall Street Journal: Companies like Epsilon know not to send a promotion for a winter coat to someone who lives in Miami, for example, or an email boasting low rates for mortgage refinances to people who don’t own their homes. “We may receive an email from the same retailer but they would be completely different,” said Dave Frankland, an analyst at Forrester Research. “Managing that across millions of customers is really complex.”

That same Forrester Research analyst told CNet that Epsilon has a LOT more info on you than your email address. We’re being told now that the hackers only got our email addresses. Maybe that’s true.