Small modern unmanned aerial systems (UAS) represent a threat against protected buildings and secure areas, which need to be taken into account in production or renovation. The threat may consist of direct attacks with harmful substances or explosive materials, or it may consist of surveillance and intelligence gathering with different sensors. This report contains a compilation of a number of commercial UAS that together with threat scenarios may be used for developing concepts for protection against UAS. The threat scenarios can be found in a separate classified memo. The report also contains a brief overview of new coming sensor systems that might be used as components in future concepts of protection against UAS.