When opening a checking account at a local bank, they run your name/SSN through ChexSystems. I am told this system only contains information pertaining to past checking and/or savings accounts and if you have a history of overdrawing such accounts or closing an account with a negative balance. Is this system also available to creditors searching for those who may have judgements against them in hopes of locating a checking account to seize? What type of sharing of information does the ChexSystem do?

They do. ChexSystem works like many other credit reporting systems.

However, there are easier ways... your accounts are opened with a SSN and your judgment is tied to that SSN... so unless you violated homeland security laws in giving a false SSN, your accounts will be found.