Or, better yet, simply imply it.
Now, if I had my druthers, we'd go the other way. Pass legislation making tobacco sales illegal, but making exceptions for certain named companies. And you appoint a judge, or committee, or special master, etc, who has to sign off on any operational changes. And, if we end up with a boring, stagnant business along the lines of a utility, well, that's exactly what we're looking for! Books are wide open, so we will see if any money is going for product placement. (Online product placement is another wide open universe which is hard to get a handle on -- unless the books of the tobacco company are wide open).
Just to make it perfectly clear, I'm all in favor of free speech for movie companies. They can make smoking as villainous, as sexy, as whatever!, as they possibly wish. They just can't accept product placement money. And since movie companies are often disorganized on the financial side, it's so much easier to supervise the tobacco companies.
In a sense, we'd be calling tobacco companies on their bluff.
For a season, they seemed to love to say, hey, you can make tobacco illegal any time you want (which they know we weren't going to do), but while it's legal we have the same rights to advertise as any other business. Fine, since you bring it up, we're going to declare you a quasi-legal business, and we will regulate you. Maybe the artful way is that the previous legal advertising like magazine ads stay the same but slowly fade away, going to every other month, then every third month. Same text, same picture, almost like it's an artifact from the past.