"Between April 26, 2015 and July 6, 2015, for a small percentage of users who began or completed an online loan application through Prosper, Prosper wrote certain personal information to local browser storage. Information written to local browser storage is contained on the computer, smartphone or tablet used to fill out your application and may be accessible to others with knowledge of data mining techniques. The impacted information included, in some cases, user name, date of birth, addresses, annual income, occupation, dates of current employment, email address, telephone numbers, employer contact information, loan amount, Prosper credit rating, bank account information and the last four digits of a user's social security number. "
Embarrassing for the frontend engineering and product team, but at least they were proactive to notify users about it. Probably pretty low risk for anyone affected