fakeroot is not a sandbox, it's just a way to have tasks which normally expect to run as root (like setting file permissions during "make install", or creating

fakeroot is not a sandbox, it's just a way to have tasks which normally expect to run as root (like setting file permissions during "make install", or creating a .tar.gz with the correct permissions) work without root. IIRC, it works through LD_PRELOAD, and it's very easy to bypass (just unset that environment variable).