These days lots of people prefer not to have a user name and password for every website that they visit - makes sense! However, for websites like ours, where you can manage your OVO products, update your personal info and top up we still need to know who you are.
So when you sign up to OVO we ask you to choose whether you'd like to have an email address and password or use your Facebook (or other) social profile to identify you. If you use your social media profiles you aren't giving us access to your Facebook account all you're doing is linking your profile to your OVO account. The only information we get from Facebook, Twitter or Google+ is your name and email address - that's all.
Don't worry this doesn't give us access to your Facebook history, profile or any other personal information.