Do the police have the right to tap my telephone?

Yes, if they can show the court that they have probable cause to believe that intercepting your telephone conversations is necessary to help solve certain crimes (such as treason, terrorism, drug trafficking, wire fraud, and money laundering).
The law considers wiretapping to be very intrusive. Therefore, it is closely regulated by federal and state law. A court will permit wiretapping only for a limited period. The authorities that listen to your telephone calls must make efforts to minimize this intrusion by limiting the number of intercepted calls to those involving the investigation. An example of this would be tapping a bookie's telephone only during the hours when it is likely that bets will be placed. After the wiretap period has ended, the authorities must inventory the calls and reveal to the court the content of the conversations they intercepted.
Less-intrusive forms of electronic surveillance are the pen register and the trap and trace. A pen register device records every number dialed from your telephone. A trap and trace records every number dialed from an outside line to your telephone. These devices do not enable anyone to listen to your conversations, as they simply list telephone numbers.
You should assume that any conversation from a jail or visitor's phone is being tapped. Do not discuss any aspect of your case with anyone in jail, except your lawyer.
It is also technologically possible for the police to tap a cellular telephone. In order to do so, they also would need a warrant. Similarly, police generally need a warrant in order to search e-mail records.
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