/usr/ is in libfastjetplugins-dev 3.0.6+dfsg-1.1.
This file is owned by root:root, with mode 0o755.
..
/usr/share/
/usr/share/doc/
/usr/share/doc/libfastjetplugins-dev/
/usr/share/doc/libfastjetplugins-dev/copyright
/usr/lib/
/usr/lib/x86_64-linux-gnu/
/usr/lib/x86_64-linux-gnu/libfastjetplugins.a
/usr/include/
/usr/include/fastjet/
/usr/include/fastjet/NestedDefsPlugin.hh
/usr/include/fastjet/SISConePlugin.hh
/usr/include/fastjet/D0RunIConePlugin.hh
/usr/include/fastjet/SISConeSphericalPlugin.hh
/usr/include/fastjet/EECambridgePlugin.hh
/usr/include/fastjet/D0RunIpre96ConePlugin.hh
/usr/include/fastjet/D0RunIIConePlugin.hh
/usr/include/fastjet/TrackJetPlugin.hh
/usr/include/fastjet/PxConePlugin.hh
/usr/include/fastjet/SISConeBasePlugin.hh
/usr/include/fastjet/GridJetPlugin.hh
/usr/include/fastjet/JadePlugin.hh
/usr/include/fastjet/CMSIterativeConePlugin.hh
/usr/include/fastjet/D0RunIBaseConePlugin.hh
/usr/share/doc/libfastjetplugins-dev/changelog.Debian.gz
/usr/lib/x86_64-linux-gnu/libfastjetplugins.so