/usr/lib/ruby/ is in libtwitter-ruby1.8 0.7.0-1.
This file is owned by root:root, with mode 0o755.
..
/usr/lib/ruby/1.8/
/usr/lib/ruby/1.8/twitter/
/usr/lib/ruby/1.8/twitter/config.rb
/usr/lib/ruby/1.8/twitter/model.rb
/usr/lib/ruby/1.8/twitter/meta.rb
/usr/lib/ruby/1.8/twitter/client.rb
/usr/lib/ruby/1.8/twitter/console.rb
/usr/lib/ruby/1.8/twitter/core.rb
/usr/lib/ruby/1.8/twitter/ext.rb
/usr/lib/ruby/1.8/twitter/ext/
/usr/lib/ruby/1.8/twitter/ext/stdlib.rb
/usr/lib/ruby/1.8/twitter/client/
/usr/lib/ruby/1.8/twitter/client/auth.rb
/usr/lib/ruby/1.8/twitter/client/blocks.rb
/usr/lib/ruby/1.8/twitter/client/base.rb
/usr/lib/ruby/1.8/twitter/client/user.rb
/usr/lib/ruby/1.8/twitter/client/profile.rb
/usr/lib/ruby/1.8/twitter/client/account.rb
/usr/lib/ruby/1.8/twitter/client/messaging.rb
/usr/lib/ruby/1.8/twitter/client/friendship.rb
/usr/lib/ruby/1.8/twitter/client/favorites.rb
/usr/lib/ruby/1.8/twitter/client/graph.rb
/usr/lib/ruby/1.8/twitter/client/search.rb
/usr/lib/ruby/1.8/twitter/client/trends.rb
/usr/lib/ruby/1.8/twitter/client/timeline.rb
/usr/lib/ruby/1.8/twitter/client/status.rb
/usr/lib/ruby/1.8/twitter/version.rb
/usr/lib/ruby/1.8/twitter/extras.rb
/usr/lib/ruby/1.8/twitter.rb