Which of the following actions is considered illegal for a security guard?

Using excessive force is considered illegal for a security guard because it violates the principles of proportionality and reasonableness that govern the use of force in security situations. Security guards are expected to maintain order and ensure safety while adhering to the law and their training, which emphasizes restraint. The use of excessive force can lead to serious legal repercussions for the guard and their employer, including civil liability for harm caused to individuals, as well as potential criminal charges.

In contrast, detaining someone for trespassing is within the authority of a security guard as long as it is carried out lawfully and the individual poses a threat or is indeed trespassing. Reporting incidents to management is a standard procedure in security operations to ensure that any issues are addressed appropriately. Taking notes during patrols is an important part of a security guard's duties, as it helps maintain accurate records of activities, observations, and any incidents that may occur.