The two legal issues associated with e-mail are retention and confidentiality. Where there is an applicable governmental records retention statute, e-mails must be preserved for the same length of time as other records. For requests under the Public Information Act or Freedom of Information Act, e-mails must be disclosed to the same extent as any other written correspondence. Attorney/client privilege, doctor/patient privilege, executive privilege, and marital privilege are the types of e-mail correspondence that might be protected from disclosure. Regarding cell phones and jamming, telephone wiretapping is generally illegal, and these laws apply to cell phones as well as to land lines. There is no right to a blanket sweep of an area to intercept any words spoken by anybody, even if the phones at issue are contraband and illegally possessed, even if one party to the conversation is a prisoner. Products that can prevent cell phones from working inside of a prison, although technologically possible, are legally unavailable. Regarding drug-detecting walk-through scanners, unless a correctional officer is also a law enforcement officer of the jurisdiction, there is no broad power to arrest or search. Moreover, if these drug-detecting devices are capable of alerting to the trace levels some claim, absent constant attention to calibration and an "expert" on hand to validate the outcome, it will be difficult to evade level challenges. When dealing with nonlethal alternative weapons as a means of applying force in a correctional setting, only as much force as is necessary to accomplish a legitimate penological purpose is legally permissible.