The LA Times article is wrong and most of the comments here are wrong too.
Merchants ALWAYS had to collect sales tax for sales to any state in which they have nexus. The only thing South Dakota vs. Wayfair changed is the standard for nexus -- previously, you had to have physical presence[1] in the state, but now states can define substantial nexus as making a certain number and/or dollar value of sales to the state.
You ALWAYS had to remit sales tax to any state you warehouse merchandise in (except for Virginia and New York, which do not consider merchandise in third-party warehouses to create nexus). Amazon ALWAYS screwed merchants over by moving Fulfilled By Amazon / Amazon Multichannel Fulfillment merchandise around willy-nilly and creating tax obligations for the merchants. (Note: Once you have nexus in a state, you have to collect and remit sales tax for ALL sales in that state, not just those from the warehouse in that state[2]). Some of their competitors, like Ship Bob and Deliverr, do the same thing -- it's all based on the nasty attitude that the consigned merchandise in their warehouses belongs to them, not the merchant (who it actually belongs to). Most merchants appear to handle this by either flagrantly breaking the law, or by being too stupid to realize they have physical presence outside their home state.
California AB 147 is one of the many bills that states are passing in the wake of South Dakota vs. Wayfair to set non physical presence based substantial nexus standards. In the case of California, AB 147 sets the threshold at $500,000 gross sales to California addresses.
The Times article says that California is going after small out-of-state merchants under the new law. Bzzt! They are going after out-of-state merchants who had physical presence and had already been shirking their tax responsibilities for years. They would have been going after those merchants anyway, AB 147 or no AB 147.
Anyone who lies down with wolves (FBA), doesn't do due diligence and complains they got fleas is getting what they deserved.
The LA Times article also says that the bill requires marketplace facilitators to collect taxes in order to help small out-of-state businesses, which is another instance of the article's author failing to read and understand anything at all. The bill requires marketplace facilitators to collect taxes because most of the merchants doing business through the marketplace facilitators fall below the $500k substantial nexus threshold and would thus be exempt; by declaring the marketplace facilitator as the retailer of record, California is able to collect taxes on the aggregate sales through that marketplace facilitator where the sales would otherwise be considered exempt.
I am not a lawyer and this is a rant, not legal advice.
[1] Or certain other things that trigger nexus, such as sales agents.
[2] Although, if the merchandise stored in that state is used only to fill orders outside that state, it doesn't create a market in that state and might be argued not to create substantial nexus. Do you feel lucky, punk?
Can't ninja edit my post for some reason.