Hey Bruce,
One would be setting the system clock back on a regular basis to prevent the end date from ever arriving.
We prevent a number of variations of the "rollback fraud". And we'll be supporting more with TurboActivate 3.2.
The second would be in cases where the tamper protection only looks at the time/date stamp on launch. The user never quits the app, so the tamper protection never rechecks the time/date.
You can check however often you like using the GetTrialDaysRemaining() function.
Does your tamper protection rely on access to the internet?
No.
If you have any other questions I'll be glad to help.