Wendy, there seems to be 2 ways to access PMs. In the upper right hand corner where is says Welcome Wendy, you last visited at "whatever time it was" - under that you can click on "Private Messages". Or if you are reading a thread you can click on the cloud-looking thing next to someone's name and chose to send a PM to them. The "friends" page is like Facebook in that everyone who visits that page can see the messages. I still haven't figured out exactly what the "Friends and Contacts" is all about - maybe there are future plans for it.
We never touch people so lightly that we don't leave a trace.