People seen taking selfies at site of hostage situation in Sydney
There is a time and place for selfies, but the site of an ongoing hostage situation is not it.
People have been posting photos on social media of themselves posing outside the police barrier at Martian Place in Sydney's Central Business District where a gunman is holed up in a cafe with hostages.
Their actions have been roundly criticised on Twitter.
But it isn't just bad behaviour that has emerged in this crisis. Actions worthy of praise have also been publicised on social media.
People in Sydney are now offering to ride on public transport with Muslims who fear they may be targets of racists because of the hostage situation.
The hashtag #illridewithyou is trending in the state capital.
It's one of the best things to have emerged out of the hostage situation, which has been under way for 10 hours.
At least five hostages have been released or escaped since the mid-morning siege began. It is unclear exactly how many hostages are still in the cafe.
Sources: AFP, Reuters, Twitter