The "For Educational Use Only" plot stamp which is found on all Autodesk educational software, is apparently becoming a very large problem for the non-educational industry.

Most major software companies offer educational versions of their software at a fraction of the retail cost, to enable legitimate (and you have to prove it!) Students and Tutors to purchase a full version of the course software for their own use, during their time at College/University.

Unfortunately, a few see this as a cheap way do some "freelancing" perhaps without realising that a plot stamp remains with the drawing at all times, even when it is imported into another drawing to be used as part of a larger project.
The plot stamp could infect the smallest block or environment and as such entire projects, by printing 
"for educational use only" on all hard copy output from an infected file.

   
There is officially no legitimate work round to this problem, but, there has been some correspondence on the drafter's forum about this, and a few suggestions on how to resolve/get round the problem from some very well informed drafters.
 
All those out there using using educational versions of AutoCAD for commercial work, please stop.
All those out there having drawings produced externally, please be very careful about checking the status of the software being used to do the work.
  
There is a program called EDU-Scan, that will tell you if your drawings are infected.
    

As they say "let's be careful out there"