OK, I'm going to be blunt here. Any online account that you have, that has a weak password, can be hacked and probably will be at some point in the future if you don't choose a secure password.
I've posted an article before about how to create a strong, secure password, but if you still have weak passwords because they are simple and easy to remember like "12345" or "password1", then hackers can easily crack it using free tools like John the Ripper to carry out what is known as a Brute-Force attack.
Brute-force attacks basically take a dictionary of words add letters, numbers, words and phrases to them and get all possible combinations of them until, eventually, the password is correctly guessed.
Contained within this dictionary of words are usually passwords that are found on the worst password lists and as such, would literally take seconds to crack.
All is not lost however, as there as there is a site which will test how secure your password actually is if you're not sure.
It's really simple too, just key in your password and it will literally tell you how long it would take a brute force attack to figure out your password using a modern computer.
Although the site and concept behind it is simple, the key thing here, is that it does force you to think about the strength of your passwords. You can see that just by adding a few numbers or characters to your password, you can dramatically increase it's security and reduce the risk that it can be guessed.
You can check out the site here, and if it says you're using a weak password, then take it as a sign that you need to beef it up immediately and protect yourself and your accounts from the bad guys.