Smart cities are increasingly at risk from hackers, who can take over technology to cause everything from fake natural disasters to disrupting emergency services.
A new report from tech giant IBM revealed the top three ways hackers could use the connected networks embedded within smart cities such as London, New York and Singapore to chaotic effect.
Natural disasters: real, or fake?
Most will remember the time human error caused a text message to be generated to all citizens in Hawaii, warning of an incoming ballistic missile that could have ended all life on the US island.
Sensors, which are used by advancing cities to track everything from weather to unattended packages in public areas, are often at risk of being hacked to trigger false alerts as a result of being attached to legacy equipment or going unchecked on a regular basis.
For example, by causing water level gauges, radiation detectors, wind speed sensors and other disaster detection and alarm systems to report incorrect data, a bad actor could cause an evacuation as a distraction from a larger crime at work.
Alternatively, should an attacker crack these systems to report that everything is normal as a natural disaster approaches, a city could suffer far worse damage. This is most dangerous when threats that humans cannot detect without technology present themselves, such as radiation.
Stuck in a jam
In a scenario favoured by Hollywood studios, police and other law enforcement will often find themselves stuck in traffic or turning into dead-ends when chasing down a criminal on the run.
Though it might seem like the work of fiction, gaining access to traffic control infrastructure could enable hackers to divert officials away from the scene of a crime by changing traffic lights to cause jams.
Re-routing enough roads to cause a gridlock in a certain destination is another way of distracting attention when something more underhand could be at stake.
Smart farming on city outskirts has become more commonplace as technology advances, with farmers using sensors to measure metrics such as humidity, rainfall and temperature to ensure a full harvest.
IBM strategists suggest that if such data were to be manipulated by outside actors, the result could be irreversible crop damage which would affect not just cities but an entire region.
If left unchecked, attacks on farming sensors could cut off food to global populations, dictate market reaction or even spread disease.
Hacks of industrial control systems have risen steadily since IBM began tracking them in 2013, and neared 3,500 worldwide in 2017. Unfortunately, IBM analysts expect this growth to continue as attackers realise the full potential of the vulnerabilities out there.
It's not an easy fix for city IT leaders, as the sheer size of connected networks in cities like London render large-scale patches and automatic updates to sensors relatively useless.
"As smart cities grow, city leaders and smart city vendors need to prioritise security by re-examining the vendors security protocols, building proper frameworks for these systems, and developing standard best practices for patching security flaws," the report said.