A very interesting and distinct approach to interruption of interception and deletion of all records related to privileged communications can be found in the Netherlands. The Dutch model of dealing with the protection of professional secrecy in practice represents a hybrid model of deletion of records and filtering and deserves additional attention. As a general rule in The Netherlands, if the conversation of persons enjoying special privilege is recorded, it has to be deleted. However, this rule has different technical implications, depending on profession. A specific technical solution is implemented for the communications of lawyers. The special system, which holds all telephone and fax numbers used by lawyers in a filter registered with the National Interception Unit, was implemented in 2011. When the interception of communication starts, the traffic data are routed to this filter and, if the system recognises the number as belonging to a lawyer, the data capture ends automatically. If any delay in transfer happens, any information already recorded is deleted. All lawyers in The Netherlands are obliged to register their telephone numbers in this system. However, this filtering rule is applicable, first of all, only to lawyers and, secondly, only to the content of voice (telephone) communications. Conversations of other professions pledged to confidentiality are not the subject of this automatic filtering. Automatic filtering is not performed for IP communications (IP traffic). There are ongoing discussions in The Netherlands on how to ensure the destruction of IP traffic because, although data can be deleted or overwritten, it is still technically possible to find them.
(Comparative Analysis în Access to Telecomunication Data in Criminal Justice (coord. U. Sieber, N. von zur Muhlen), Duncker & Humblot, decembrie 2016, la p. 49)