How is that better, really? Run tcpdump or ettercap... Either of the
tools are off the shelf.
And if the site is using a self-signed cert, how does a 3rd party tcpdump
manage to get a *decrypted* datastream? Yes, you can still do traffic analysis
on the "X talked to Y with packet sizes A, B, and C" level, but you can't
look at the data.