This is a broad topic. Briefly:
In the United States the National Security Agency has been in the news and it operates according to its own playbook.
Generally, legal authority for recording conversation is governed by state and Federal Laws. You should check the laws in your particular state before recording a conversation since state laws vary on whether one or both parties must be informed of the recording. Law enforcement must obtain a court order.
No. As long as you are a party to the conversation then you do not have to tell them you are recording them.
Recording of the phone conversation.
A surveillance system is a series of video camera or cameras and recording devices. They are used to monitor the security of a home or other property.
Forever if they feel that there is something to keep. Otherwise banks keep Video surveillance for 10 years.
Surveillance VCR's so not have built in cameras. Today most people choose to use DVR's for their surveillance needs, since VCRs have constraints on them due to needing to change tapes and short recording times. This site has great information on all the different surveillance equipment http://www.alarmsystemreviews.com/security-camera-recording-methods.html
A Recording
In most states as long as one party of the conversation, which could be the one doing the recording, has knowledge that they are being recorded, recording a phone conversation is legal.
no law
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One way to keep accurate records of one to one communication is by recording the conversation. Recording the conversation is great when you have to be accurate.
because he has that much swag
Many police departments today use various forms of spy surveillance equipment, such as audio recording devices, video recording and bug sweeping equipment. This equipment allows the police department to provide solid audio or visual evidence for investigations.