Port 443 (https) is a far more immediate problem. Currently nothing is recorded other than the fact that a connection has been made, and this fact has been used for years by people who want to get things working through corporate firewalls. Things like online purchases, unauthorized vpns, and private emails. A lot of competently written malware probably does the same, only nobody notices because current tools can't break ssl-encrypted communications to audit them.
Someone really needs to take sslsniff and turn it into a proper administrative tool. Admittedly it currently works through an IE mistake, but sysadmins can configure computers on the network to believe that you are a valid CA.