Killstreak Points

For some reason there are multiple ways to get killstreak points. one ways is to obviosliy get a kill. another is to get two assists if you have hardline pro/. another is to capture a flag in the game mode "Caprture the Flag. another is to caputer flag in "Dominiation." another is to plant a bomb in "Demolition." and another is to plant a bomb in "Search and Destroy." and for some random reason you just get random kills