On April 28, New York City didn't care whether I puffed on an electronic cigarette in a bar or anywhere else; beginning on the 29, it did. Vaping (the lingo for puffing an e-cig) is now, like smoking, prohibited in public places such as parks and beaches, as well as in private places of employment such as bars, restaurants and offices. Unlike smoking, which has been known for decades to be risky, vaping isn't known to harm anyone. (A few studies have suggested that it is, but there's no conclusive, widely accepted body of research. As support, see the two articles linked in my penultimate paragraph.) So the obvious reason for putting limits on vaping -- that it's bad for you, and maybe for others as well -- doesn't apply. Nonetheless, opponents of vaping have advanced a handful of misplaced or exaggerated worries.

• E-cigs -- because of the nicotine or the other ingredients -- might turn out to be harmful later. That's true, but it doesn't justify imposing a widespread restriction on them now. A proven threat to public health can legitimately be regulated or even banned outright, which explains controls on tobacco products. There's no simple principle, though, when it comes to feared threats. On WNYC-FM last December, I heard someone (whose name I failed to record) who was involved in the New York City Council discussion on e-cigs say, "There's no evidence that these are harmless." So we should assume that everything is harmful until proven otherwise? Well, there's no evidence that overbearing nannyism is harmless either. As a matter of fact, there is a definite harm any time individual liberty is curtailed. So we're accepting a loss of freedom now in return for a purely speculative payoff sometime later. The City Council appears to be saving citizens from a possible future. Have its members been watching too much bad sci-fi?

• Traditional tobacco companies are entering the market for e-cigs; if we allow vaping, they'll benefit. This takes two forms. One, companies such as Lorillard -- which bought the Blu e-cig maker in 2012 -- are going to profit from selling e-cigs; two, Big Tobacco is only getting into e-cigs to improve its image. Both these anxieties amount to changing the subject -- which is e-cigs, not their manufacturers -- and they're nonsensical to boot. It's as if we've mentally painted tobacco companies as black-caped, mustache-twirling villains, and it'd be morally confusing to let them do something good. Sigh... E-cigs offer an alternative to people who do smoke or who otherwise might smoke traditional cigarettes. The product should be welcomed, from any company that chooses to make them, large or small -- and some of those companies are small.

• E-cigs may be a gateway to cigarettes, or they may restore some sheen to the badly tarnished reputation of smoking. The gateway argument is backwards: no one I know has gone from e-cigs to cigarettes, whereas I do know people who've given up smoking and replaced it with e-cigs. It's always possible that someone will progress from the safe thing to the decidedly unhealthy thing, but it's hard to see how that's the fault of the safe thing. And I think the borrowed-reputation fear is backwards too. Cigarettes are a very useful prop, as actors and directors know, and, if you suppress what you know about smoking, you can still sense the sophistication, glamour, ruggedness or what-have-you with which movies and still photos have depicted smoking. With an e-cig, you can pretend you're Humphrey Bogart or Lauren Bacall without risking your lungs.

• Some people don't want to be around e-cigs. That sounds vague, but it seems to be true. I know people who declared some time ago that they would never vape in a bar; I don't know anyone who ever vaped at work; and I know bars and restaurants that had already forbidden e-cigs before the City Council passed its law last December. Vaping seemed to have become impolite before it was banned. One of my friends, offering his guess as to why, told me, "E-cigarettes have a smell." That was news to me, but something must explain our newfound desire, in this city that's often riotously malodorous outdoors, for atmospheric purity in bars, restaurants, etc. Whatever the reason for the preference, it's not obvious that everyone feels that way. Did New York's ban need to be total? Leaving workplaces aside, couldn't our places of pleasure have been asked simply to declare themselves as vaping or non-vaping areas? You could've had bars that forbid it, while I'd have some that allow it. That pluralistic dream must've been too namby-pamby for New York's city government.

I've spoken only in local terms, but this is an international issue. The European Union, the World Health Organization and America's Food and Drug Administration have enacted, or announced plans to enact, regulations on e-cigs. There are reasons for doubt about these too, which are well expressed in editorials from The Economist and the Financial Times.

A final thought: in a New York bar, I can still poison my liver as much as I want, unless my server cuts me off, but I can no longer puff an e-cig. That kind of craziness makes me feel like lighting up out of spite.