Do NOT answer if someone asks 'can you hear me?': Major phone scam edits your response to make it appear as if you've agreed to a huge purchase

Do NOT answer if someone asks 'can you hear me?': Major phone scam edits your response to make it appear as if you've agreed to a huge purchase 

Scammers have already fooled people in Florida, Pennsylvania and Virginia, and now experts are warning that it is set to make its way over the pond and affect UK users.