A lot has been said about this already, but using strong passwords that are unique for each online service is still one of the best things you can do to prevent problems. If Adobe were hacked, for example, and the password you used to sign up for Adobe product downloads was compromised in the breach, that wouldn’t hit you too hard — unless, of course, you use the same password for my online bank account and my PayPal credentials that I use for Adobe.
That may sound a little fantastical, but that is how it happens. One site gets compromised and loses data, and the username-and-password combinations found at that site are then tried against a large number of other online resources.
So, having strong passwords that are unique to each site or service you are using is incredibly important. A good password should include upper and lowercase characters, numbers, and special characters available on your keyboard, such as the “tilde” or “@” signs. A good password is also no less than 8 characters long, and preferably in the 12-16 character range.
How are you supposed to remember all those passwords? Get a good password manager, or set up an encrypted file that contains your username and password list (which is the basic function of a password manager). However, remember that if your Credentials List is not encrypted (either by you or your password-management app), it’s worse than having a single, awful password.