I don't care about giving a five digit zip code because it's not a unique identifier. I never remember the four extra digits that point to my house, anyway, so they can't get those out of me.
I can't think of any large cash transactions we've done except to buy traveler's checks for going overseas. We get them at the AAA and they've never say boo about it. Of course, they have our member information, so perhaps their computers fill the forms out automatically. That would be easy, since it's probably the only kind of large cash transaction they do regularly.
It's long been the case that bank deposits and withdrawals of $10,000 or more had to be reported to the Federal government. I was blissfully unaware of all the new scrutiny of the smaller transactions. The effect of them is to make money less liquid. It doesn't really have value if you can't spend it. It's a good argument for gold and silver coinage, if your printed money is only spendable with government permission. However, the downside is that there is only so much new production of precious metals in the world and it tends to be a lot slower than the rate of population growth, meaning a hard currency has some inherent deflationary influence as there is no chance for each generation to have as much of it per capita as the last one did. Quite a complicated mess.
Buying money orders or cashier's checks or preloaded visa cards or anything else like that are all potential money laundering devices. Laundering means cleaning. If you have marked bills, you change their form by getting the intermediate instrument, then cashing the intermediate instrument in. Bingo. No marked bills. All cleaned up. Counterfeiters like to do that, too, for obvious reasons.
Still, cash is king in many instances. Privately selling anything to strangers is one example. Computers make it so easy to counterfeit cashier's checks and money orders it is all too frequently woe to the person who accepts them for such a sale. Rackets abound wherein drug gangs use counterfeit M.O.'s or cashier's checks or traveler's checks to buy used cars from people, then drive them straight to Mexico and sell them there for real money. It takes days and sometimes weeks for a bank to figure out the counterfeits are bad. Often longer than clearing a personal check. Their system is antiquated and slow. So those instruments are virtually worthless now, to my mind, and I'm surprised there's still so much business in them as trustworthy instruments. I wouldn't sell a gun or a car to any stranger for one.