Apparatuses, devices, systems, and methods are provided for prevention of tampering with cables and associated systems. In one aspect, an anti-tamper adapter is provided that can inhibit or prohibit cable tampering for existing cables. In a further aspect, dummy plugs or blocking plugs can employ disclosed anti-tamper adapters to facilitate blocking ports or outlets that are intended to remain undisturbed for a period of time. The provided embodiments can economically and flexibly facilitate cable tamper prevention in a wide array of cable technologies.