Let’s face it, it’s been a scary year in data security for companies and their customers alike. Hackers have been slipping through corporate computer defenses like they’re Swiss cheese.

On Thursday, J.P. Morgan Chase JPM said that a cyber attack over the summer may have compromised information about 76 million households. That included customer names, addresses, phone numbers and email contact information. In addition, the breach affected about seven million of J.P. Morgan’s small businesses customers. Overall, it may have been the biggest cyber attack in corporate history.

Here’s a look at some of the biggest breaches at some top companies.