MITM can't prevent leakage for a determined spy or insider trader. I worked at a bank, they blocked FB etc with a blacklist, but it was very easy to circumvent.

MITM can't prevent leakage for a determined spy or insider trader. I worked at a bank, they blocked FB etc with a blacklist, but it was very easy to circumvent. Whitelist might work, but it would create too much management headache.