One of the ways in which criminals gain access to potential victims is by obtaining lists of names, addresses, phone numbers, credit card numbers, etc.
There is an underground market where these lists are shared, sold and traded. A list of 32,000,000 client names, email addresses and passwords was stolen from RockYou, a company that writes software for Facebook and other web sites. That list and others found its way onto the internet where criminals share them, so; if your information is on any of those lists then uncounted numbers of crooks around the world already have your personal information. Banks, insurance companies, hospitals and government agencies have all publicly admitted to having their computerized records compromised. There are undoubtedly many more thefts of personal data that have gone unreported.