Transmissions can be blocked, but its whether you want to go into the skeptical world of carrying a frequency blocker with you at all times. That would mess up quite a few frequencies, and could effect some of the emergency services communications which could potentially be a crime depending on where you live.
@o_e_l_e_o,
I've heard somewhere about a virtual chip that can be inserted in a human body anywhere (most probably wrist) and they can generate invoices and even send/receive Bitcoins through the same. If that's true, even if the attackers know that "this guy is having Bitcoins" but are unsure where did he store them, how will they plan and attack such person? If such a device can be stored in us, why can't we have some sort of device stored in our body too that can alarm Police by sending them necessary details like our live location as well as a message like "Emergency, need help, stuck somewhere!" that we may use by just tapping that area in our body whenever such scenario takes place?
It doesn't matter
where you store your Bitcoin it only matters that you
have Bitcoin. In most scenarios its better to just give up a small amount of money than get harmed. By refusing to tell them where your Bitcoin is it could potentially put you in a life alternating situation which to be honest I wouldn't be willing to risk for a small amount of cash. This is why the point of carrying a small amount of cash is a good idea, and not bringing your whole stash with you. If you're smart, and keep your Bitcoin separated the thief won't be able to prove that you own more than what you give to him on the spot.