/usr/lib/pyshared/python2.7/google/protobuf/internal/_net_proto2___python.so is in python-protobuf 2.4.1-1ubuntu2.
This file is owned by root:root, with mode 0o777.
It is a symlink to /usr/lib/pyshared/python2.7/google/protobuf/internal/../../../../../python2.7/dist-packages/google/protobuf/internal/_net_proto2___python.so