Torsten Spindler Christoph Wartmann Ludger Hovestadt Daniel Roth Luc J. Van Gool Andreas Steffen Privacy in video surveilled spaces. 199-222 2008 16 Journal of Computer Security 2 http://iospress.metapress.com/content/gwx9247178441p0t/ db/journals/jcs/jcs16.html#SpindlerWHRGS08