This is exactly what Larry Wall warned against when he said in the Llama book on p. 339: "
Enforced privacy tends to get in the way of people trying to get their jobs done. Perl's philosophy is that it's better to encapsulate one's data with a sign that says IN CASE OF FIRE BREAK GLASS. You should respect such encapsulation when possible, but still have an easy access to the contents in an emergency situation, like for debugging."
Still, if you really want to tie everyting down, have a look at pages 339-346 of the Llama book.
CountZero
"If you have four groups working on a compiler, you'll get a 4-pass compiler." - Conway's Law