(b) the path through which the communication was transmitted. Preservation of data 17. (1) If a police officer is satisfied that: (a) data stored in a computer system is reasonably required for the purposes of a criminal investigation; and (b) there is a risk that the data may be destroyed or rendered inaccessible; the police officer may, by written notice given to a person in control of the computer system, require the person to ensure that the data specified in the notice be preserved for a period of up to 7 days as specified in the notice. (2) The period may be extended beyond 7 days if, on an ex parte application, a [judge] [magistrate] authorizes an extension for a further specified period of time. Interception of electronic communications 18. (1) If a [magistrate] [judge] is satisfied on the basis of [information on oath] [affidavit] that there are reasonable grounds [to suspect][to believe] that the content of electronic communications is reasonably required for the purposes of a criminal investigation, the magistrate [may] [shall]: (a) order an internet service provider whose service is available in [enacting country] through application of technical means to collect or record or to permit or assist competent authorities with the collection or recording of content data associated with specified communications transmitted by means of a computer system; or (b) authorize a police officer to collect or record that data through application of technical means. Interception of traffic data 19. (1) I f a police officer is satisfied that traffic data associated with a specified communication is reasonably required for the purposes of a criminal investigation, the police officer may, by written notice given to a person in control of such data, request that person to: (a) collect or record traffic data associated with a specified communication during a specified period; and (b) permit and assist a specified police officer to collect or record that data. (2) If a magistrate is satisfied on the basis of [information on oath] [affidavit] that there are reasonable grounds [to suspect] that traffic data is reasonably required for the purposes of a criminal investigation, the magistrate [may] [shall] authorize a police officer to collect or record traffic data associated with a specified communication during a specified period through application of technical means. Evidence 20. In proceedings for an offence against a law of [enacting country], the fact that: