Sensitive information including logins to social media accounts was among the data exposed in what some believe is the largest breach in U.S. history.

One of the key risks of a data breach this big is how easily cybercriminals will be able to access multiple accounts, especially for those who reuse passwords. A survey from NordPass indicates that as many as 62% of Americans, 60% of Brits and 50% of Germans admit to reusing passwords across multiple online accounts.

Researchers said “it’s impossible to tell how many people or accounts were actually exposed.” They cautioned that some reports claiming that Facebook, Google, and Apple accounts were leaked are a little misleading.