/usr/lib/x86_64-linux-gnu/libvpx.so is in libvpx-dev 1.3.0-3+deb8u1.
This file is owned by root:root, with mode 0o777.
It is a symlink to /usr/lib/x86_64-linux-gnu/libvpx.so.1.3.0
/usr/lib/x86_64-linux-gnu/libvpx.so.1.3.0