From the Divorce section of How You Can Avoid Legal Land Mines by Joseph S. Lyles (2003).
Many people who divorce see it coming, but given the emotional turmoil they are in, it is not surprising that they fail to take sufficient steps to protect their finances from the machinations of their estranged spouses.
One of the precautions that spouses typically fail to take is closing or depleting joint accounts of all types. Credit card accounts can be difficult because any existing balance will prevent them from being closed. But you should be able to get the account coded so that no further charges can be made. If you don’t feel comfortable about completely depleting a join account, then at least do so by one-half the balance.
A joint account that is often overlooked is a checking account credit line, usually established to prevent bounced checks. Unfortunately, the first spouse to think of it can use the entire line of credit by withdrawing cash, yet the other spouse is still liable on the debt to the bank.
The Lesson: As soon as you hit the choppy seas of marital discord, you should close, suspend or deplete your joint accounts.