One of the key conditions to prosecuting an action for invasion of privacy is whether or not the person has a reasonable expectation of privacy. The courts across the country are finding with more and more frequency that no reasonable expectation of privacy exists with E-mail in the workplace setting. And a court in New Jersey reviewed whether a spouse's accessing of E-mails of the other spouse on a home computer violated New Jersey wiretap laws (modeled closely on the ECPA), finding that no expectation of privacy exists on a home computer when the family is involved and that the seized E-mails could be introduced as evidence of infidelity. This case focused largely on whether the spouse violated the section of the ECPA and the state equivalent by accessing "stored communications." The state judge ruled that E-mails, once saved on the hard drive automatically in the sent E-mail folder, were no longer stored communications under the act and were legally accessed, copied, and admitted into court.

So, unless the family court judge is willing to take action, the person doing the spying may find their actions go largely unchecked. (I suspect that this will change as more and more family court matters involve unauthorized access of someone else's account.)

Hmmm ... not enough to scare you off? Worried about what your spouse is doing right now online? How does someone get started spying on their significant other? There are Web sites devoted exclusively to unfaithful spouses and their online communications. ChatCheaters.com is one of those sites and offers lots of resources, advice, and software applications to its users. It was created by a man who found his wife had run off with a man from New Zealand she had met online. It contains recommendations for spying software and surveillance equipment. Recently, more than 3,000 individuals have visited the site daily, up from its previous 500 daily site visitors. If the increase in traffic is any indication, more and more people are worried by cyberinfidelities. Professionals in this area, including divorce lawyers and family counselors, believe that about 50% of all infidelity cases involve the Internet in one way or another.

It's so easy to snoop, too. Not many of us think about implementing security measures to keep our loved ones out of our computers and E-mail accounts. Typically, we reserve that for outside intruders. Usually, when relationships are working well, the partners share their passwords with each other. Then when things start falling apart, they forget to change their passwords and their former partners use this security breach to dig around for evidence of infidelity and wrongdoing. Even if the password is changed, password hints are often easily answered by others who know the user well. Hints such as the name of your pet or your best friend's name don't provide much security protection from a former spouse.

Sometimes, in an effort to get revenge, a spouse will access the instant messaging or E-mail account of the other spouse and change the passwords and password hints, locking them out of their own account and safeguarding the evidence of infidelity or wrongdoing at the same time.

You don't have to wait until you can sleuth out their login and passwords, either. Software is now available from reputable companies that will let you snoop via remote control. If you can get access to their computer directly, you can install various programs that will give you a snapshot of their screens and communications, or even a copy of everything they do and say online, and everything said to them. These reports are then made available on the network or on that PC itself.

Getting to the computer directly is too inconvenient? No problem. You can now remotely install the program on another's computer in secret by E-mailing the program to the person you want to spy upon. In security circles we call these Trojan horses and their transmission is illegal. I suspect that these commercial trojans are no different. In an apparent attempt to get around the legalities, the software manufacturers advise you not to use this software unless you own the computer or have the permission of the computer owner for its installation. Purchasers are also warned that without being the owner or acting with the owner's permission you may be violating federal or state law. No mention is made of two-consent laws.

The instructions then suggest that you change the default name of the install.exe file to make it more likely the E-mail will be opened and the product installed without the person knowing they're being spied upon. Once the E-mail is opened, the program installs itself secretly.

Once installed, the program sends a copy of any E-mails, chat, instant messages, and surfing activities of the person being spied upon to the snooper in real time. You can set up special reporting that sends only the E-mails or instant messages that include certain words, such as sexual terms or love. And it can record both sides of the communications, which may implicate the two-consent rule is some states.

Scary? You bet! Yet, when we're worried about what our significant others are doing, we will stoop (or snoop) to anything to find out what's really going on. And promises of computerized reports of everything they're doing and saying online are tempting. But users of these products may find themselves facing more than an irate ex-spouse. They may find themselves facing an angry judge, civil damages in a breach-of-privacy lawsuit, possible jail time, and serious fines.

Parry Aftab is a security, privacy, and cyberspace lawyer, as well as an author and child advocate. She advises some of the world's leading companies on privacy and online security matters, including cybercrime and abuse prevention and risk management. A substantial portion of her time is devoted to Internet issues involving children, from equitable access to privacy, safety, and helping develop quality and reliable content for children. She also donates her time to running the world's largest online safety and help group, WiredSafety.org, which is comprised of thousands of volunteers from around the world.

To discuss this column with other readers, please visit the Talk Shop.

To find out more about Parry Aftab, please visit her page on the Listening Post.