A tamper resistant keypad includes one or more key assemblies having a resilient key member and a contact. The blocking cartridge can be released only by an authorized institution or person equipped with a connection-releasing technology that is matched by the manufacturer to the composition of the adhesive system. The PDA may also be a phenolic resin which comprises at least 5 mol % of a recurring monomeric unit having at least one phenolic hydroxyl group and at least one alkali solubilising group. The magnetic interaction may cause the crossbar to serve as one or more detents that movably affixes the stand in a desired position relative to the tablet.