The COINTELPRO operators targeted multiple groups at once and encouraged splintering of these groups from within. In letter-writing campaigns (wherein false letters were sent on behalf of members of parties), the FBI ensured that groups would not unite in their causes. For instance, they launched a campaign specifically to alienate the Black Panther Party from the Mau Maus, Young Lords, Young Patriots and SDS. These racially diverse groups had been building alliances, in part due to charismatic leaders such as Fred Hampton and his attempts to create a "Rainbow Coalition". The FBI was concerned with ensuring that groups could not gain traction through unity, specifically across racial lines. One of the main ways of targeting these groups was to arouse suspicion between the different parties and causes. In this way the bureau took on a divide and conquer offensive.