I have read your "reply" with "things in quotation marks" and have "evaluated its merits." Here is my "reply:"
For starters- the cost of doing business is calculated and accounted for in all successful business models. Cashiers (like in the grocery store) are paid to handle cash transactions. Companies all over the country are paid to secure cash and transport it from place to place. This affects the prices that you pay for things in cash, although it is not always immediately apparent. These costs are passed on to you indirectly with absolute inevitability. While legal tender may be used for "all debts public and private," there is no guarantee of a cost-free transaction. You also currently have the option of paying for things via credit card or debit card, which you are confusing with some mythical form of electronic currency. Using these cards costs money, as it is a SERVICE which serves in the place of a cash transaction.
In your third paragraph, you are failing to account for the many moving parts which make the simple entry of your debit or credit card number into a website and instantly allow you to distribute your income to any number of places world-wide. These also must be paid for, just as cashiers and cash transport services. They are often less expensive. Note that it is not mandatory to use this system, just very very very convenient - to the point where other systems seem ridiculous (ie flying to Sweden to use cash, in my previous post.)
The cost to provide this service includes several things, such as insurance against theft, asset protection, fraud detection, datacenters, phone banks staffed with customer service reps, etc. Just because you can use a debit card online or in person which takes a cash value out of your bank account and distributes it to someone else does not make it equivalent to cash. Credit and debit card companies charge businesses to use their services because it is value-added. It is not a tax on cash because it is not a cash transaction, and despite its ubiquitous nature, debit and credit transactions are not mandatory. The words you are looking for are "fee for service." You do have the option to use cash at the place of business from which you wish to purchase, as defined by legal tender.
Finally, if a business such as Visa or Paypal makes you mad with their decisions to cease doing business with a person or organization, you may feel free not to bless them with your business. I do not disagree that the decisions regarding Wikileaks were likely politically motivated. Personally, I don't agree with many things that Paypal does/has done, so I don't give them any of my money if I can help it. However, these businesses are not constitutionally bound in any sense to provide their service to anyone. Visa/PayPal voluntarily bound themselves with an agreement called their Terms of Service, which is up to their interpretation. They do not have to support free speech (especially not of a foreign national?) if they choose not to.
The representation you seek is your choice to do business with them - vote with your wallet!