Gang Stalking is really a covert government or police investigation. It's similar to Cointelpro or red squads, and it's being used on a lot of innocent people to ruin them and make them look crazy. Gang Stalking is all about government disinformation, and using civilian spies/snitches to help with stalking and monitoring innocent people.
Jim was placed under covert investigation by his employer because of his whistle-blowing. Mistakenly he termed it gang stalking, which made him sound crazy.