[kybernetikos]

Work could be done to make it more usable. With a phone, it could be a button you could press just by holding it. With a smart watch, it could be hooked into any kind of bluetooth sensor. The point is that in normal society, you don't have that much control over who and what gets into proximity with you, and having a system where anything that does get into proximity can take money from you without you even acknowledging that in any way is just a bad way of doing things.