There is a defense that many don't realize regarding patents.

If you maintain proper records of your proprietary information and discoveries, a subsequent granted patent by someone else cannot prevent you from using your process. You can even sue to invalidate the granted patent as a requirement is that the patent not be in the realm of prior art.

Most people seem to think that a granted patent can take away your right to use a process you've been using before the claim date. Not if you've documented everything internally.

aka j