There are risks with any online service. Hence I would give some general advice that would be applicable for any online service.

• The best thing to do is to have a different password for each online service - it also makes sense to use a password generator and utility to save your passwords (but do remember that will be the weakest link in the chain
• You can have multiple mail accounts (to declare as your email ID), one for all your confidential information and secondary mail id for services for which you are not fully confident about
• you could also sign up using the secondary account for these services, to limit your risks/exposure.
• Another option is to use single sign-on to avoid creating passwords at multiple services (also remember tips about using multiple accounts/ you can make one for suspicious services
• It also helps to segregate your accounts (and not keep all your information one place)

These are some simple tips that first come to my mind, will do add a few more a si remember them