When you write e-mail, always consider the possibility that it can be quoted against you
Your e-mail, especially with your ex and especially if you're involved in a divorce or child custody case, can be used against you. In most jurisdictions, your e-mail can be "discoverable" as well as admissible in a court case, meaning that the other party often has a right to demand that you produce copies of e-mails (or any transcripts that you have kept of instant messaging conversations, including automatic archives) before trial. The other party may offer them into evidence at trial if proper authentication is established. Once such a request has been made, it is too late and it is improper to delete them. When you write to your ex, try to step back and imagine what a third party, such as a judge or your child's attorney, would think if he or she were reading it. The same goes for an instant messaging conversation. Keep e-mails and IMs that you have received from the other party, and make sure that you keep the date and time information and the content intact, without editing.
Be careful what you say at MySpace, Facebook and other social networking sites
Even if you're not a celebrity, the content of your MySpace, Facebook or other social networking website can be of great interest to someone - the other party in your divorce/custody case and his or her family and friends. If you keep an online journal or "blog," be careful what you say. Don't assume that only your online friends will ever read it. Talking online about that wild party and the crazy things you did last night may not be in your best interest! In most jurisdictions, your "admissions" or confessions can and will be used against you. Nicknames for yourself and for other people aren't enough protection to keep your remarks truly anonymous; your ex or soon-to-be-ex probably knows those nicknames already and can search for them online.
Keep your passwords private and change them often, especially after changes in your household
Don't assume that your friends-only entries in your online journal, or your private e-mail to a third party, will be safe when you're involved in a Family Court or divorce case. If your spouse, your in-laws, your boyfriend/girlfriend, your roommate or your friend knows any of your passwords, your privacy is always subject to compromise, and the information obtained by using your password is not always automatically excluded from use in court. Don't rely on the idea that "if you got that illegally, then you can't publish it or use it in court" - that's not necessarily true! Your private comments about the other side, the child, the child's attorney, your in-laws or even the judge might eventually end up in evidence, even after you believe that you have deleted something or have locked it as private. The safest policy is: don't put anything out on the internet, even under password protection, that you wouldn't want to see published under your name in a courtroom!