The case against parental surveillance devices. Big Mother is Watching
Now, the obvious danger of such devices is that they raise paranoid parenting to an even more extreme level, thereby further depriving children of the chance to test their capacity for independence.
The more subtle, but equally important, objection to spyware is that it isn't good for parents either. By making snooping relatively impersonal, these technologies prompt mothers and fathers to bypass important moral questions about their relationship with their children. If it's all right to scrutinize your daughter's text messages, then it should be OK to read her diary. If it's all right to electronically monitor her driving, then it should be equally kosher to get in to your own car and follow her. Yet there are good reasons most sane adults would balk at these low-tech invasions of their children's privacy.