I use my paypal card reader! Both when holding garage sales and when visiting, it's pretty normal and a lot of people use it without blinking.

If you pearl-clutching Christians fearful of change don't want a cashless society, maybe stop pouring all your support behind the political powers that want to see giant megacorporations flourish and crush out small businesses. The people who want to control your rmoney are not the banks nearly as much as the Walmart down the street that can now take credit card payments simply by glancing at the store as you pass.