5.  Details of the applicants can be found in the appendix. 6.  At the time of the events giving rise to the applications, the applicants were all serving prison sentences in the Edirne F-type Prison. 7.  On 21 June 2005 the disciplinary board of the Edirne F-Type Prison decided to intercept letters sent by an association, D.D. (“the association”), to the applicants on the ground that their content included propaganda for an illegal organisation and referred to activities in support of the illegal organisation and of people on a “fast to the death”. 8.  On 28 June 2005 the Edirne Enforcement Court dismissed an objection lodged by the second applicant against that decision. 9.  On 18 July 2005 the Edirne Assize Court upheld the Edirne Enforcement Court’s decision. 10.  The applicants lodged an initial individual application with the Court (no. 45443/05) raising substantive complaints under the Convention, which was subsequently declared inadmissible on 12 October 2017 under the single-judge procedure. 11.  On 14 September 2005 Mr Tamer, the applicants’ lawyer at the material time, sent a letter to the applicants asking them to fill out and sign the forms of authority that were enclosed with the letter, to authorise him to lodge an application on their behalf with the Court concerning the disciplinary board’s decision to intercept the letters sent by the association (see paragraph 7 above). He explained that he was sending his letter by registered mail because he had not received a reply to his previous letter with the same content. He also mentioned that the forms of authority were not required by the Court immediately on bringing an application and that they could be submitted at a later stage. In addition, he asked the applicants to inform him in the event that they did not want to pursue their application before the Court. 12.  The administration of the Edirne F-Type Prison believed the contents of the letter of 14 September 2005 to be suspect and therefore lodged a request with the public prosecutor on 21 September 2005 for a decision to refer the matter to an enforcement court to determine whether the material sent to the applicants included objectionable content. 13.  On 25 October 2005 the Edirne Enforcement Court allowed an application by the prosecutor and examined the contents of the letter. It decided that, under section 5 of Law no. 5351, the letter and the forms of authority should not be handed over to the applicants because it considered that Mr Tamer’s request for the applicants to complete the forms of authority for the purpose of bringing an application before the Court did not constitute a permitted professional activity (serbest çalışma hayatına aykırılık) but instead pressurised and incited the applicants to institute proceedings. The decision was served on the applicants on 17 November 2005. 14.  On 29 November 2005 the Edirne Assize Court dismissed an objection lodged by the second, fourth and fifth applicants and upheld the Edirne Enforcement Court’s decision of 25 October 2005. 15.  On 1 December 2005 Mr Tamer filed a complaint with the Edirne Chief Public Prosecutor’s Office against the governor of the Edirne F-Type Prison on the ground that he had neglected his official duties by not forwarding Mr Tamer’s letter of 14 September 2005 to the applicants. 16.  On 26 December 2005 the Edirne Chief Prosecutor’s office decided not to prosecute the governor in relation to Mr Tamer’s complaints, since the letter in question had been withheld from the applicants as a result of the implementation of the Edirne Enforcement Court’s decision of 25 October 2005. 17.  An objection to the prosecutor’s decision, lodged by Mr Tamer, was dismissed by the Kırklareli Assize Court on 19 April 2006. 18.  In the meantime, on 23 November 2005 Mr Tamer wrote to the Committee of Ministers of the Council of Europe informing it that the Edirne F-Type Prison administration’s refusal to give the applicants the letter in question had impaired his ability to lodge an application with the Court and constituted a violation of the European Agreement relating to Persons Participating in Proceedings of the European Court of Human Rights. 19.  On 22 February 2006 the Registry of the Court sent a letter to Mr Tamer acknowledging receipt of his letter dated 23 November 2005, addressed to the Committee of Ministers of the Council of Europe, as indicating the applicants’ intention to lodge an application with the Court and invited him to submit a duly completed application form. 20.  On 19 October 2006 the applicants’ representative sent an application form to the Court. Their application was registered as application no. 4536/06. 21.  On 30 March 2007 the Registry of the Court sent a standard letter to the applicants’ representative in connection with application no. 4536/06 confirming, inter alia, receipt of their application and requesting the representative to provide forms of authority in connection with that application. 22.  On 18 April 2007 the applicants’ representative sent a copy of the Court’s letter together with forms of authority to the applicants and requested them to fill out the forms of authority in connection with application no. 4536/06. 23.  The Edirne F-Type Prison administration believed the contents of the letter of 18 April 2007 to be suspect and therefore lodged a request with the public prosecutor on 24 April 2007 for a decision to refer the letter to an enforcement court to determine whether the material being sent to the applicants included objectionable content. 24.  On 9 May 2007 the Edirne Enforcement Court allowed an application by the prosecutor and examined the contents of the letter. It decided that, under section 5 of Law no. 5351, the letter enclosing the forms of authority should not be handed over to the applicants, on the same grounds as those given in its previous decision dated 25 October 2005. The decision was served on the applicants on 18 May 2007. 25.  On 1 June 2007 the Edirne Assize Court dismissed an objection lodged by the second and fourth applicants and upheld the Edirne Enforcement Court’s decision. 26.  On 21 November 2007 the applicants’ representative lodged another application with the Court, complaining that the decision of 9 May 2007 had violated the applicants’ right to effectively pursue their application with the Court. Their application was registered as application no. 53287/07. 27.  All the applicants submitted forms of authority in respect of each of the present applications to the Court on 5 April and 21 October 2010 respectively. 28.  The relevant provisions of Law no. 5275 on the enforcement of sentences and preventive measures as in force at the material time provided as follows:
Section 59 – Right to consultation with a lawyer or a notary
“...
(2)  Consultation with a lawyer or a notary may be carried out in working hours except for weekends and public holidays, in a place reserved for that purpose within the sight but not hearing of officials.
...
(4)  [as amended by section 5 of Law no. 5351] A lawyer’s documents and files related to defence and his or her records of the meetings with his or her client shall not be subject to examination. However, if it emerges from documents or other evidence that visits by lawyers to a person convicted of the offences set out in section 220 of the Criminal Code or sub-chapters 4 and 5 of Chapter 2 of the Criminal Code are serving as a means of communication with a terrorist organisation or of committing a crime or otherwise jeopardising the security of the prison, the enforcement court may, at the application of the prosecution, impose [the following measures]: presence of an official during the lawyer’s visits; verification of documents exchanged between the prisoner and his or her lawyers during such visits; and/or confiscation of all or some of these documents by the judge.
...”
Section 68 – Right to send and receive letters, faxes and telegrams
“(1)  With the exception of the restrictions set forth in this section, convicted prisoners shall have the right, at their own expense, to send and receive letters, faxes and telegrams.
(2)  The letters, faxes and telegrams sent or received by prisoners shall be monitored by the reading committee in those prisons that have such a body, or, in those which do not, by the highest authority in the prison.
(3)  If letters, faxes and telegrams to prisoners are a threat to order and security in the prison, single out serving officials as targets, permit communication with terrorist or criminal organisations, contain false or misleading information likely to cause panic in individuals or institutions, or contain threats or insults, they shall not be forwarded to the addressee.
Nor shall [letters, faxes and telegrams of the type described above] written by prisoners be dispatched.
(4)  Letters, faxes and telegrams sent by prisoners to authorities or to lawyers for the purpose of their defence are not subject to monitoring. ” 29.  Details of the relevant provisions of the prison regulations in force at the material time can be found in Tan v. Turkey (no. 9460/03, §§ 13-14, 3 July 2007) and Mehmet Nuri Özen and Others v. Turkey (nos. 15672/08 and 10 others, §§ 30-34, 11 January 2011). 30.  Section 55 sets out a prohibition on legal advertising as follows:
“Lawyers are prohibited from advertising or engaging in any conduct which may be regarded as soliciting for the purpose of offering their services ...” 31.  Article 3 of the European Agreement relating to Persons Participating in Proceedings of the European Court of Human Rights, ratified by Turkey on 6 October 2004 and in force as of 1 December 2004, reads as follows:
“1.  The Contracting Parties shall respect the right of the persons referred to in paragraph 1 of Article 1 of this Agreement to correspond freely with the Commission and the Court. 2.  As regards persons under detention, the exercise of this right shall in particular imply that:
(a)  if their correspondence is examined by the competent authorities, its despatch and delivery shall nevertheless take place without undue delay and without alteration;
(b)  such persons shall not be subject to disciplinary measures in any form on account of any communication sent through the proper channels to the Commission or the Court;
(c)  such persons shall have the right to correspond, and consult out of hearing of other persons, with a lawyer qualified to appear before the courts of the country where they are detained in regard to an application to the Commission, or any proceedings resulting therefrom. 3.  In application of the preceding paragraphs, there shall be no interference by a public authority except such as is in accordance with the law and is necessary in a democratic society in the interests of national security, for the detection or prosecution of a criminal offence or for the protection of health.”