protected void respondToOpenDoor(Matcher m, Tweet msg) {
		String username = msg.getUser().getScreenName();
		this.door.open_door();
		try {
			this.nearbyUsersSemaphore.acquire();
			this.messagesToPublish.add(String.format("@%s opened the door.", username));
			String deviceId = this.db.getDeviceIdFromUsername(username);
			if(!this.nearbyUsers.contains(deviceId)) 
				this.nearbyUsers.add(deviceId);
			this.nearbyUsersSemaphore.release();
		} catch (InterruptedException e) {
			
		}
	}