Everyday, everywhere - to many, smartphones have become an extension of the human body.
They connect us to the rest of the world, but with that power comes the risk they can be used to spy on us.
Now, a New Zealand tech expert says an iPhone security flaw could have caused major financial havoc worldwide.
A targeted cyber-attack against a man in the United Arab Emirates revealed the breach, which is being described as the first of its kind.
"Listen in on the person whose phone it is, record through their camera, go through their emails - just about anything that someone could do, but without the person knowing what's going on," says Gorilla Tech's Paul Spain.
An Israeli company has been accused of making spyware to target a human rights campaigner in the United Arab Emirates.
Ahmed Mansoor received two texts to lure him into clicking a link which would have turned his phone into an eavesdropping device.
"It's called a remote jailbreak. Now this sort of attack, this is the first time we've seen it in the wild," says Citizen Lab senior researcher Bill Marczak.
Mr Spain says although this was a targeted attack, it could have wreaked havoc if it had been sent out widely.
"Used on a widespread basis you know it could cause some pretty major, major issues, you know potentially to financial systems," says Mr Spain.
The public is concerned about the issue as well.
"I feel like it's an issue for teenagers because they're roaming the web and stuff like that and on all sorts of apps, but they don't really know what they're doing," says a phone user.
"I like to do everything in person because the internet is not the safest place. I know that," says another.
Apple has scrambled together a software update which it's urging its customers to download to shut down the security breach.
However it's got people asking why a company with billions in the bank still gets bugs in the first place.
Mr Spain says they're just a reality of software.
"Software companies are always trying to reduce the chance of there being these sorts of bugs but we continue to seem them on a pretty regular basis," he says.
So as long as they exist, it's a case of buyer beware. Always ensure you never click on suspicious links - and always update your software.