Ok... perhaps I should clarify here ....
You are the producer of a file ... for whatever reason you wish to lock the drawing so that it may not be manipulated outside of your computer .... mind you that is your computer only .. the one with CADlock installed .... lets presume now you have some 200 workstations....these drawings must be shared among other people for different aspects of the drawings AND your client who may require these drawings must ALSO have CADlock, simply to view the file .....
Now ... with 200 users and one client ... 201 seats @$400 ea = $80400.00 ..... is it worth that expense? Yeah .. in a small office the problem is not so big, but are you going to tell your client that he has to buy a $400 seat of CADlock to view his file?
The main issue is not to disallow a person to view the drawing ... you could simply password protect the drawing to do that .. then CADlock is of no consequense anyway ...
Could there be an embedded macro that prevents modification
Personally I have seen little advance in this area... although I did preview a beta of a program that touted prevention of drawing manipulation while allowing drawing access....but it never made it passed the beta stage due to severe issues with drawing header corruption....
It would be nice to have the ability to do that....