Although not an expert on these matters at all, it is my understanding that, in previous years, the 'party' element had got a bit out of hand at Sebring.
Hence, when I was there in March, I noticed that there was a strong, but silent, police prescence in parts of the camping and trackway areas.
Apparently, the craze at one time was to wedge vast quantities of pissed youths in the back of pickup trucks (usually standing) and then hoon around the trackways.
All very well until some unfortunate fell out and was run over and killed. So now the police seem to enforce a responsible attitude to drinking and driving within the site.