About a month ago, Dropbox, one of the larger cloud storage companies, confirmed that it was indeed hacked. They've now deployed a 2-Step Verification process before allowing any new devices or sessions to access your account. I highly recommend you activate it ASAP if you use their service!
Simply log into your Dropbox web account online
Go to Settings by clicking on your Account name on the upper right hand side of the website
Click on the Security tab
Then scroll down and enable the Two-Step Verification.
Follow the instructions.
Make sure you have your mobile phone handy since Dropbox will send you a verification code. Or if you have an Android or iOS device, you may use an authenticator app and scan the QR Code instead.
This may be a bit of an inconvenience, but it's much better than having your data compromised.