Wiktionary
tappable
a. Capable of being tapped.
Usage examples of "tappable".
In the American Embassy General Schultz was uncomfortable too, horrified that Jack should express such robust views over an easily tappable cellular phone.
The Boskonian would not trust any ordinary, tappable communicator beam, and he certainly would not be such a fool as to send any written or taped or otherwise permanently recorded message, however coded.