Supporters say electronic cigarettes are saving thousands of lives, detractors believe they could be dangerous and are making smoking seem sexy.
But following a decision in the European Parliament their availability will be restricted in the future.
MEPs voted to introduce new regulations which will control what kind of e-cigarette can be sold in member states.
The e-cigarette gives people a nicotine hit without the toxins that are present in tobacco cigarettes.
For many smokers they have been the key to them giving up as they replicate the smoking experience much better than nicotine patches, gum and sprays.
But some doctors have been concerned that there may still be long-term health problems from using them.
Some campaigners also fear that e-cigarette use in public is normalising smoking again and may end up being a gateway to tobacco for young people.
The European Parliament hasn't banned their use. But it is going to impose restrictions on the kind of e-cigarette that can be sold.
In particular, users - or vapers as they call themselves - will no longer be able to get some of the reusable and refillable devices that deliver the biggest nicotine hit.
The growing community of vapers believe it's an assault on a product that is saving their lives by removing the temptation of tobacco.
Christena Heseltine from North Shields in Tyneside has been using e-cigarettes for five years.
She credits them with improving her health, but she also enjoys them. Her daughter Kirsteen is another user, and husband Ron, who has terminal oesophageal cancer, has recently joined them.
It's unclear whether smoking caused his cancer but vaping has allowed him to continue to enjoy nicotine without smoking.
Christena is outraged at the European Parliament's decision. She thinks it'll ramp up costs for vapers but also make it impossible to obtain the high-nicotine devices she often uses.
She says many frustrated users will go back to smoking, while others - her included - may look to the black market.
She said: "I'll be forced to break the law, become a criminal, and that is scary.
"The vaping community has worked hard to make sure it's as safe as possible. We have worked with trading standards to ensure the nicotine juices are safe and properly labelled.
"But now if I go to the black market, I won't know whether the nicotine I'm getting is safe, so the work we have done will have been for nothing."
Vapers did have some allies in the European Parliament. North East Conservative MEP Martin Callanan, fought against the EU proposals, and is disappointed most of his colleagues backed them.
He said: "This is going in completely the wrong direction. E-cigarettes have the ability to convert thousands of smokers to vaping as they call it. That is a thousand times safer than smoking tobacco cigarettes.
"As a harm reduction measure we should be encouraging people to take up e-cigarettes not making it more difficult to obtain them. This is a very bad day for public health."
Fresh North East was set up in 2005 to tackle the problems caused in an English region with the highest death rates for smoking-related diseases.
They do see a role for e-cigarettes in weaning people away from tobacco, but have been concerned about how they've been advertised.
Director Ailsa Rutter believes the regulations won't stop e-cigarettes being available for the people that want them.
She said: "These regulations are really quite light-touch. Elsewhere in the world, some people want them banned and Fresh certainly wouldn't support that.
"What we want to see is them being even better quality and safer. We are concerned about children getting hold of them at the moment. Some may have very high doses of nicotine in them, in others people may be being ripped off as they have no nicotine present at all.
None of that will cut much ice with the vaping community though. They believe the freedom to enjoy e-cigarettes is under assault.
But more importantly they also feel the EU has undermined what they see as the most successful way of cutting the number of smoking-related deaths.