"The Court reiterates in this connection that removal of the right to vote without any ad hoc judicial decision does not, in itself, give rise to a violation of Article 3 of Protocol No. 1 (see Scoppola (no. 3) [GC], cited above, § 104). With a view to securing the rights guaranteed by Article 3 of Protocol No. 1, the Contracting States may decide either to leave it to the courts to determine the proportionality of a measure restricting convicted prisoners’ voting rights, or to incorporate provisions into their laws defining the circumstances in which such a measure should be applied. "