security issues in fitness wristband

Source:
https://www.google.com.au/search?q=fitness+wristbands&biw=1920&bih=979&source=lnms&tbm=isch&sa=X&ei=RvwiVcuYFsjf8AX3sICABw&ved=0CAYQ_AUoAQ&dpr=1#imgdii=_&imgrc=CxB-7aRWayO7iM%253A%3Bctx78xlfYA9xfM%3Bhttp%253A%252F%252Fthe-gadgeteer.com%252Fwp-content%252Fuploads%252F2013%252F02%252Flarklife-_1.jpg%3Bhttp%253A%252F%252Fthe-gadgeteer.com%252F2013%252F02%252F19%252Flarklife-tracking-fitness-wristband%252F%3B500%3B365