Thirty-nine state attorneys generals plan to examine the popular e-cigarette company's marketing and sales practices.
The new law has taken effect, raising from 18 the minimum age for such purchases.
In the future, the streaming service's original programs for young viewers will be cigarette-free "except for reasons of historical or factual accuracy."
E-cigarettes, which are the most common tobacco product among youth, are included in the underage ban.
The wealthy California city's council voted unanimously to end tobacco sales but exempts hotels and plush cigar lounges.
Some advocates are worried that efforts to raise the legal smoking age to 21 are being used as a "Trojan horse" for large tobacco companies.
Companies like Juul may have to pull their flavored products from California retailers.
President Trump Made Growing Hemp in America legal again. Now most states plan to promote hemp farming.
Secondhand smoke is toxic — especially to children.
The measure would not apply to e-cigarettes, cigars or chewing tobacco