You're talking about Sales and Use tax, and the laws vary state by state. Some states have no Sales/Use tax at all, and there is no requirement for taxpayers to report out of state/country purchases. There is currently no federal sales tax.
Most, if not all, states that have Sales/Use tax do require you to report taxable (not everything you buy is taxable) purchases if you did not pay sales tax or, at least in the case of California, if you paid less sales tax than you would have owed had you purchased the item in your state. (I.e, if I go out of state to purchase items and pay 5% sales tax there, I owe the difference to California between that 5% and my county's sales/use tax rate).
IF the out of state/country purchase is consumed/used out of state, I do not owe California anything for those purchases - I do not have to pay a "use" tax for something I didn't "use" in California.
I do notice that you like to call people names, which I find immature and boring. I was a bit startled at your disparaging comments about "gypsies" and their habits in your country, and you seem to also like to attack Americans in general and those who are financially better off than you as well.
If you really feel that disparaging others is the best use of your time on this forum and in life, I'd encourage you to find a more positive outlet - you may find yourself enjoying more success.