Preventive: (Adjective) Designed to keep something undesirable such as illness, harm, or accidents from occurring.

The requirements to be one of Britney Spears' backup dancers just got about as tough as MLB, because her dancers are now all required to submit to drug testing.

"They all had to be drug tested and, if they didn't pass, they were fired," the insider says.

"I don't think it's a common practice, but each artist is different," Baker tells E! News, referring to the drug-testing issue. "Everyone is just trying to safeguard against any foreseeable problems." (Source)

If they really want to safegaurd against any "foreseeable issues" what they really ought to be testing for is vaginal beards, douchey wife-beaters, aspiring rap careers and super powerful sperm conductive to impregnating pop stars. You know what they say, those who ignore history are doomed to have Britney get knocked up by some dumb wigger and go AWOL again for the next four years.

More of Britney pretending not to still be crazy at some Christmas thing last week: