Since the individual states started cracking down on and enforcing it for internet sales. Not all states have done it yet but it's only a matter of time before they all will want their slice of the pie.
https://smallbiztrends.com/2019/01/list-of-states-with-internet-sales-tax.html
Some friends that use to do the e-bay thing to make some extra spending money gave it up because they are now required (or at least supposed to) to track, collect, and pay taxes on their sales. They decided that it wasn't worth the headache or the possibility of an audit if they didn't do it.