I found this rather interesting and thought you might too in case you wanted to go down this path ;) What makes a phone call harassing? When someone calls and uses obscene or threatening language, or even heavy breathing or silence to intimidate you, you are receiving a harassing call. It is against the law in California and other states to make obscene or threatening calls. (California Penal Code section 653m, Penal Code section 422-422.1) How often do I have to get these calls to make it harassment? Just one unwelcome call can be harassing; but usually your local phone company will not take action unless the calls are frequent. However, if a call specifically threatens you or your family with bodily harm, the phone company will generally take immediate action. Who should I contact when I get harassing calls? Local phone companies have varying policies on whether to call the phone company or the police first. Some recommend that you first call the phone company's business office and explain the problem. A representative will connect you with the "annoyance desk." Other phone companies may require you to file a formal complaint with local law enforcement before they will deal with the matter. To find out what your phone company's policy is, contact the business office and ask for assistance. For serious threats, if life or property are threatened, or if calls are obscene, you should call the police and file a report. Provide as much information to law enforcement as you can. Indicate the gender of the caller and describe the caller's voice. Note the time and date of the call(s). What did the caller say? How old did he/she sound? Did the caller seem intoxicated? Did he/she have an accent or speech impediment? Was there any background noise? Was a phone number/name displayed on the Caller ID device? What can my local phone company do if I am receiving harassing calls? If the calls are frequent or particularly threatening, the phone company can set up a "Trap" on your phone line. The Trap allows the phone company to determine the telephone number from which the harassing calls originate. You must keep a log noting the time and date the harassing calls are received. Traps are usually set up for no more than two weeks. The phone company does not charge a fee for Traps. A phone company service called Call Trace may also be able to help track down harassing calls. Immediately after receiving a harassing call, you enter the code *57 on your phone and the call is automatically traced (1157 on rotary phones). Call Trace is easier than using a Trap since the customer does not have to keep a phone log. But Call Trace technology works only within the local service area. (Look in the "Customer Guide" section of the phone book or the phone company's web site for a description of your local service area.) Call Trace must be set up in advance by the individual receiving harassing calls, and it requires a fee for use. However, in situations where the phone company would ordinarily use a Trap, you might not be charged if the phone company suggests that Call Trace be used as an alternative. Be sure to ask. The information collected from Call Trace or from a Trap is turned over to law enforcement personnel, not the customer. Law enforcement officers try to stop the harassing calls by either warning or arresting the harasser. With both Call Trace and a Trap, your phone conversations are not listened to or recorded by the phone company.