Former FBI agent: eBay users should reset all passwords
22 May 2014 Last updated at 12:13 BST
A former FBI agent has urged eBay users to change all their passwords, to prevent them from being hacked on other sites.
EJ Hilbert, a former special agent in cybercrime, also warned that the leaked data could be used for identity fraud and to even obtain mortgages in the US.
It comes after a cyber-attack compromised the eBay system between late February and early March.
Hilbert advised BBC Radio 5 live's Wake Up to Money that a memorable long phrase, with over thirty characters would be the "perfect password."
eBay said it had no evidence of there being unauthorised activity on its members' accounts.