For one, I think they should investigate actual suspects, not do blanket surveillance on everyone, only to leak that personal data later. Using cash is an exam

For one, I think they should investigate actual suspects, not do blanket surveillance on everyone, only to leak that personal data later. Using cash is an example of sort of "opting out" of mass surveillance. Other comments in this thread have pointed out that there's a cost to businesses to accept cash. There's also a cost to consumers to pay with cash. But some choose to do it for privacy benefits. I think it's nice to be able to have that choice. A person may sometimes want to sell their information to the credit card companies and get "points". Other times they may not. > If you disagree, please share how you believe detective work is compatible with strong privacy. Detective work seemed to happen just fine before digital money when there was only cash. Blanket surveillance didn't happen because it was impossible or too costly to do. I'm not saying anything about this theoretical "strong privacy". > Cash has its own problems though - it's much easier to use it to avoid taxes, launder money, etc. when using cash. Why should law abiding citizens have their rights taken away because some people abuse it? We have the second amendment protecting rights that are arguably much more dangerous, despite how they're abused by criminals. In my opinion, privacy advocates are asking for something much less, and with much less potential for violence -- the ability to make a purchase when they're perfectly law abiding, without some rando recording that, and having it leaked on the Internet for god knows what to happen with it.