Earlier quoted context omitted.
How is it "sane" for companies not to be able to control and monitor their own Internet connections? People clearly do abuse those connections to violate IP, confidentiality, and insider trading agreements.
The people doing that just turn on encryption. The people that get in trouble for using encryption just encode the cyphertext as codewords in their email. Monitoring communication is mathematically impossible these days. The deep problem is that employees have a lot less to lose than employers. If you leak a picture of the next iPhone to your competitor, you lose, at most, everything you own. For most people, that's…
Your logic says, "wiretaps are meaningless, because monitoring voice is mathematically impossible". Leaving aside the fact that many things that are mathematically possible (such as undetectably encoding high-entropy data as a greater volume of low-entropy data) are practically infeasible, what's your point? Wiretaps, for instance, are clearly incredibly valuable.