To keep up to date with the recent data breaches, one can use DataLossDB. It is a research project aimed at documenting known and reported data loss incidents world-wide.
For something more visual, Information is Beautiful presented world’s biggest data breaches as bubbles of various size depending on the amount of records lost. Short stories and explanations are also available for some of the incidents.
For real-time information, Google developed the Digital Attack Map. It is a live data visualization of DDoS attacks around the globe, built through a collaboration between Google Ideas and Arbor Networks. The tool surfaces anonymous attack traffic data to let users explore historic trends and find reports of outages happening on a given day.