In a previous post RicodJour wrote...
I don't think Adobe's PDF security is as secure as you may think:
http://www.cs.cmu.edu/~dst/Adobe/Gallery/
There are a whole host of "password recovery tools" that will strip
the encryption and open up the file to editing.
Send me one of your drawings and I'll show you what I mean. {Pat, you
still have those FLW drawings you told me about last year...? I think
I have a workaround.}

And on another PDF security issue, potentially more damaging for a
much larger group of people:
http://news.com.com/2100-1002_3-6147428.html


Rico:

The point of the PDF security is not to prevent fraud, but to make it more
difficult for the average user. Nothing can prevent someone from stealing
your signature and seal. Color copiers make this an all too frequent
occurrence.

--
Bob Morrison, PE, SE
R L Morrison Engineering Co
Structural & Civil Engineering
Poulsbo WA
bob at rlmorrisonengr dot com