Same happens in Colorado, they legislated themselves a new stream of Sales & Use Tax, so now I get a list of all purchases to submit at tax time to pay any "uncollected sales tax". I believe I saw a recent report that all but 4 or 5 states either have something similar already or in the works. So you'll see it more and more.
Also look for many china shipments to go up within a year, if the US follows through with dropping out of the 140-year Universal Postal Union (or negotiates such that China pays more than "developing country" rates). All the cheap postage to slow boat it to the US could be impacted.