This new device links to your smartphone and transmits a picture of attacker to the authorities when deployed. But is this the right approach for preventing harassment and assault?

From faux-phone stun guns to lipstick tasers, the market for women's self-defence products is thriving in the US. Enter The Defender, a high-tech smartphone-linked pepper spray that has taken crowdfunding platform Indiegogo by storm.

With the push of a button, The Defender will not only spray the assailant, but also snap a photo of them, fire it off to the local authorities, and blast an alarm to alert passersby. It hit its target goal of $100,000 within 24 hours, and there are currently 2,100 units on pre-order. It's set to be in stores in the US in 2015. How did it come about?

"The Defender started with a conversation about safety for a college student," says Ryan McManus, co-founder and marketing director of Pangaea Services, who developed The Defender. "We hope that the technology will interest men and women, and men have been very interested in The Defender for their wives, daughters, sisters, and mothers," he says.

The gadget is connected via Bluetooth to an app on your smartphone, sending the image of the attacker to a 24/7 monitoring system, which then forwards it to the emergency services along with GPS coordinates, which means the police can be dispatched straight away. It also doubles up as a medical alert device; pressing a second button informs health services of a serious assault.

Pepper spray is a long-established tool for self-defence, but the Defender has updated it for the internet age, according to McManus. "The service of responding to an alert and contacting the authorities is the real value," he says.

The Defender joins a flourishing industry of self-defence devices for women in the US. Several websites specialise in female-oriented protection products. Women on Guard offers a pepper spray disguised as a hot pink perfume bottle for $12.95 (around £8), and Damsel in Defense carries what it calls "hermergency kits", which contain a waterproof whistle, a first aid kit and an LED flashlight, among other items. Another site, Rose Guardian, sells sharp-edged, cat-shaped "self-defense key-chains" and on Etsy you can find handmade switchblade necklaces.

Most of these devices, including the Defender, may be classified as offensive weapons, and therefore illegal, in the UK. McManus, however, says his device can be adapted for legal use: "For the UK market, there are alternative self-defence sprays that could be used."

There's another issue: are these devices helping or hindering efforts to tackle sexual harassment and assault cases? Orla Sheehan, newly elected president of the Feminist Society at the University of Southampton, thinks the latter: "One of the fundamental issues with the Defender as marketed to women is that we should not have to carry one of these to be safe. I can't live my life in preparation for an attack."

There are also concerns that the Defender's technology could be misused; and then there is its hefty pricetag: "It costs $179 for the Defender and one year of their monitoring," says Sheehan. "To me, this says: if you are rich, you can be safe. We should not be living in a world where a woman's income determines her safety."

McManus seems to agree. "We should be educating people on identifying and preventing sexual harassment," he says. On the issue of misuse, he says the company will not tolerate it. "If misused, the camera on the Defender captures the incident and that will be evidence." The company will also be giving a portion of profits to organisations that educate and protect victims of assault.