If your inquisitive neighbor is a real eavesdropper, she runs a real risk of being dropped by the company. After all, the more time she spends eavesdropping, the less time she spends working. Sooner or later, her performance is going to drop too.
At the same time, what can you be talking about that is so interesting to her? Is she really all that interested in your business calls, or have your personal calls and conversations piqued her interest? It is possible that if you spend more time on work-related discussions, and less time on personal discussions, she will lose interest in you and find another target. She may even consider targeting her own work.
The next time you find her hovering over your cubicle, tell her on the spot that this behavior is distracting and disturbing and you want it to stop. If the problem continues, you should mention it to your manager.
An additional interesting point is that workplace privacy is actually becoming extinct, as increasing numbers of employers are monitoring workplace behaviors, phone calls, e-mail, and Internet activity. In fact, your neighbor probably does not realize that while she is eavesdropping on you, management may be eavesdropping on her.
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