Sydney’s CBD has been in lockdown for five hours as a gunman holds people hostage at a Martin Place cafe.

Authorities have been warning people to stay inside their buildings, while premier Mike Baird said people should try and get home as normal, but the siege has brought the city to a halt, and severely disrupted public transport, with buses bound for the city stopping short of their destination and a number of key roads in the CBD closed.

And that’s when the smartphone taxi app Uber stepped in. Instigating its controversial “surge pricing” which often sees fares jump when the weather is bad or other critical incidents occur.

At one stage Uber Black, which offers hire cars, jumped to four times the normal price, with a minimum ride charge of $100.

That meant a ride to Sydney airport from the CBD was around $150.

Uber splits the fares with the drivers, taking 20% on a surge deal.

UberX, the private driver option, also had surge pricing, making them more expensive than a normal taxi – despite being marketed as the low-cost option. But with authorities warning motorists to stay out of the CBD, few drivers took up the option.

But the backlash against the move was swift, with many venting their displeasure with the company for what they saw as commercial opportunism.

It obviously led to a rethink by Uber, who 20 minutes later, jumped back on Twitter just after 2pm and decided to make all rides home from the CBD free.

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