Mindjack

Start a new campaign, or select scene 1-0.
Straight off the bat go into wanderer mode ( + ), cycle one person to the right () which should be a citizen. Mind hack () them and make sure you clear our all enemies in that room (should be one guy).

Now go back into wanderer mode ( + ), and mind hack () the same citizen, rinse and repeat and you'll have the achievement in no time.

One good way to combine acheivements is through multiplayer. Join another game on the blue team, and while the host is playing the level, just float as the wanderer and jump into any civilian on the level, go gung ho with the B attack, and when you get downed, you can jump into another civilian. This way you progress the 100 civilains, 100 attacks, 50 finishing moves, and 5,20 and 50 Blue hacker help acheivements!!