Especially this guy, who did it twice: http://en.wikipedia.org/wiki/Vassilis_Paleokostas
http://en.wikipedia.org/wiki/Containment_building
"In 1988, Sandia National Laboratories conducted a test of slamming a jet fighter into a large concrete block at 481 miles per hour (775 km/h). The airplane left only a 2.5-inch-deep (64 mm) gouge in the concrete. Although the block was not constructed like a containment building missile shield, it was not anchored, etc., the results were considered indicative. A subsequent study by EPRI, the Electric Power Research Institute, concluded that commercial airliners did not pose a danger."
WRT prisons, landing with an airplane is going to be challenging (minimum landing distance is 500m) and taking off is likely impossible (minimum take-off distance is 520m[1]). Given the improbability of leaving the prison, it will be a self-correcting issue. ;-)
[1] http://www.aircraftcompare.com/helicopter-airplane/Terrafugi...
http://en.wikipedia.org/wiki/List_of_helicopter_prison_escap...
If you break those rules, even innocently, the FAA can come down hard on you by revoking your license and fining you thousands of dollars. Depending on how sensitive the area is and how suspicious you appear they can send other aircraft to your location and (in the case of the DC FRZ) potentially shoot you down. Once you've been indoctrinated into the system you learn to be extremely aware of where you are, what is nearby, and to stay away from sensitive areas.
*There are ways, at least for private pilots, to legally fly over a lot of restricted areas but it's much easier to just fly around them or not bother.
I doubt it'll be an issue for the same reason I doubt it's been a major issue that bolt / wire cutters are available in any hardware store. The physical barrier isn't the only thing that prevents people from crossing it and causing havoc.