snitchjacketing or badjacketing isn't an east coast term. it refers to someone calling someone an informant or a "snitch" to out them from a group. the FBI and other law enforcement groups use real informants to plant evidence on people that they may be a snitch to then create infighting or a witch-hunt. it also makes it difficult for those reffered to as snitches, who are in-fact snithes, to work within the movement they come from, because people are weary of such a rumor possibly being true.
when not used by cops/ security forces/ etc it's usually employed by someone as a low blow, because they can't come up with anything of any merit to accuse, denounce, or argue with someone about.
Ex.Hey Duke, have you cashed your check from the FBI yet?
^ example of snitchjacketing.