How can someone take advantage of something every player has access to at all times. It works for and against Special users, if you see your radar ping heavily towards a doorway behind a wall, then its safe to assume that the person sitting round the corner has a close quarters weapon type. Best bet is to reposition and hold a safer angle unless you wanna keep challenging a shotgun/fusion rifle in a confined space which clearly you won't win. Radar has saved my bacon plenty of times where you see it ping with a more intense shade, indicating to me a player is most likely camping extremely close to me or on their way to push me. If anything the radar was the tool that gave me the heads up on this and gave me an opportunity to back up and reposition. Just play to your playstyle and its advantages instead of falling into the trap of another player's playstyle.