If terror was the intention, it might have worked; because Sydney is terrorized.  Downtown Sydney near Martin Place is locked down after attackers took several hostages at the Lindt Cafe.  The Harbor Bridge is open, according to Fairfax Media.  But the Sydney Opera House was evacuated following the arrival of a suspicious package.  Click through for some live coverage links.

ABC is providing live coverage on its main website and on YouTube:  

http://www.abc.net.au/news/2014-12-15/hostages-sydney-cafe-martin-place-police-operation/5967232

http://www.youtube.com/watch?v=nvzpSvyyZis

Fairfax is also providing live coverage:
http://www.smh.com.au/nsw/lindt-chocolat-cafe-hostage-drama-in-martin-place-sydney-20141215-1278cx.html
As is The Guardian:

http://www.theguardian.com/australia-news/live/2014/dec/15/sydney-siege-reports-of-hostage-situation-inside-martin-place-cafe-live

And 7 News:

http://au.news.yahoo.com/video/watch/17174725/yahoo-7-live-sydney

The common Twitter hashtags are #SydneySiege and #MartinPlace

The New York-based news site Mashable is reporting that Uber is reportedly charging its users a minimum of A$100 to get a ride out of Sydney’s CBD.  That’s four-times the normal rate for Uber’s ride service, and apparently is happening because “demand is off the charts”.  People on Twitter aren’t terribly happy about it.

Details are few about what’s going on:  At least one armed person is holding around 13 or more hostages in the Lindt Cafe.  7 News reports that a middle man with a black bandana appears to be directing the hostages.  The hostages appeared to have been directed to hold a black flag with white Arabic script up to a window.