Since TAX and DTV keep coming up and we keep seeing headlines that thai authorities want to get stricter with enforcing the tax

.....Are there any countries currently which successfully enforce tax on money brought into their country (and how do they do it?)?

....Will the thai tax authorities go straight to Thai banks (if you have one) and request they share information on how much money is being brought in?

....With people without a thai bank it seem almost impossible for them to enforce tax on remittance income

....I'm probably gonna go back to working in thailand because I don't suddenly want to be lumped with a 200,000 k baht tax bill etc...