What we have to remember is that VERY few people hit the 25 fish limit at any time other than the spawn and even then it is confined to just a few easily accessible areas. Other than spawning time at those few places white bass are mostly ignored in NC.
Like Jbare said there are other areas that aren't as easy to access or to corner the fish. As long as they have those places to spawn the population should be pretty safe from overfishing.
Might be a better approach to make it illegal to release any white perch caught. How about a series of white perch tournys ...... base it on number of fish caught and NOT released!