For as long as divorce has been a part of society, spying and tracking of one estranged spouse by another has existed. People who are battling over child custody have looked for evidence of neglect. Spouses in Arizona trying to work out alimony have kept a close eye out for any infidelity. Spying can extend to property division issues as well, such as is the case with hidden assets.
However, these days the key to successful spying during divorce proceedings may be entirely digital, and not only in high-asset divorces. Spyware placed on a home computer shows keystrokes of a conversation in which one spouse regrets the burdens of children. A GPS tracker placed on an automobile indicates that it was parked for an hour outside a "no-tell motel" when the spouse claimed to have been at work. And bank account records can be searched in nanoseconds for anything that might make the targeted spouse look bad regarding an divorce legal issues.
That said, most observers agree that installing tracking or other spyware on a partner's cellphone will likely be judged illegal and any evidence gathered thereby inadmissible in family law court. Also, while the illegally gained information may not be used in court, an allegation that an illegal tracking method was employed just might be. Lawyers can't stop their clients from e-spying, but they can certainly discourage it.
Emotions often run amok during the end of a marriage. This is why many couples choose to have their respective family law attorneys assist with the negotiation of a settlement agreement. Having legal counsel might prevent a hasty decision.