The other patent on the case was filed in 2002 and granted in 2009, so it'll expire in 2022. (starting in 1995 patents expired 20 years past the application date).
1. File Patent Application.
2. Wait a while.
3. Submit something that delays the Application process.
4. Repeat 2-3 until you decide its time to let your Patent be Granted.
What the PTO did to combat this is starting in 1995(?) they changed it where the life of the patent is 20 years past the application date, instead of 17 years past the grant date.
There are two patents on the case.
US Patent No. 5838906
Filing Date 1994-10-17
Grant Date 1998-11-17
US Patent No. 7599985
Filing Date 2002-08-09
Grant Date 2009-10-06
Clearly the second one was the one that they were waiting on to sue people over.