A new report from MPs has certainly generated a new talking point - not least among vapers and smokers taking a break from their desks.
It has raised again the questions of whether e-cigarettes are a positive force for public health and whether they could yet cause harm to users. Both it seems could be true.
The Commons' science and technology committee comes down strongly in favour of vaping as a vehicle to help smokers quit.
Its report says that about 470,000 smokers are using them as an aid to help them give up the habit and tens of thousands are successfully quitting each year.
The MPs believe transport and other public places should be more sympathetic to vaping. That means not bracketing e-cig users with smokers and banishing them to the street.
One tweet on Friday morning underlined the frustration of one rail traveller: "No-one on the platform and it's totally uncovered. I was vaping. A guard walked 100 yards and told me it's not allowed. I said 'but it's open air and there's no-one about. Rules are rules' he said!"
On the other hand, some of those who don't smoke or vape take exception to the idea of being in close proximity to an e-cigarette user.
To quote another tweet: "Not in public places please - I don't want my world filled with sweet smelling clouds of vapour. All mixed together from different peoples tastes. Yuk!"
People of this persuasion might not be happy to hear that the committee advocates "non-vapers having to accommodate vapers".
So is vaping safe?
There is no definitive answer to that.
The clinical regulator, NICE, makes the point that as e-cigarettes have only been on the market for about a decade, there is no authoritative research yet available. It may take several more years for such research to emerge which can show beyond doubt that vaping does not affect users' lungs or other aspects of their health.
This then is a debate about whether clear gains now in terms of getting smokers off tobacco might be outweighed in future by adverse health effects which only emerge after detailed research.
The MPs on the committee, public health authorities and many health campaigners are strongly of the view that fairly certain gains now are more important than a possible long-term risk.
Critics are adamant that it's too soon to give a clear-cut message to consumers.
The MPs also want to see a clearer lead from the NHS in advocating e-cigarettes. They are disappointed that a third of mental health trusts in England won't allow vaping on their premises, even though smoking among people with mental health conditions is much higher than for the general population.
At smoking cessation clinics some local authorities suggest vaping, but others don't.
The committee also wants to see more e-cigarette brands cleared for medicinal use. This would allow GPs to recommend or even prescribe them if they wished, subject to the views of their commissioning groups.
There is one brand, eVoke, which has had such approval from the Medicines and Healthcare Products Regulatory Agency but, curiously, it has not yet been marketed to consumers.
Intriguingly, the company which owns the brand is British American Tobacco. Company sources have indicated that the brand is "not likely" to be taken any further as the vaping market has moved on since eVoke was developed and consumer preferences have changed.
This is still a debate clouded with uncertainty but the select committee report has allowed some of the fog to clear.
It has moved smoking higher up the agenda of important public health issues, with growing pressure on NHS leaders and ministers to think about a way forward.