What is a common deterrent method used by security companies?

The correct answer highlights the importance of visible security measures as a deterrent to potential criminal activity. When security companies implement visible security signage and deploy uniformed officers, they effectively create an environment where individuals are less likely to commit a crime due to the awareness that security is present. This visibility can make potential offenders think twice, as the risk of being apprehended increases significantly when they know that security personnel are actively monitoring the area.

In contrast, while high penalties for violations can serve as a deterrent, they are often not visible or immediate in the way that security personnel and signage are. Frequent social media updates can enhance community awareness but do not provide real-time deterrence on the ground. Training employees in customer service focuses more on interaction and customer experience rather than addressing security issues directly. Therefore, the most impactful method among the options provided is the visible presence of security personnel and signage, which effectively communicates that security measures are in place and actively enforced.