It is important to define and choose the appropriate physical and emotional boundaries you will enforce when people interact with your dog. Some things are going to be OK, some things are not going to be OK. A couple of examples...
It is not OK for someone to hurt your dog: a physical boundary.
It is also not OK for someone to terrorize your dog: an emotional boundary.
When working with students, I help them to figure out and choose appropriate boundaries for their dogs, especially if kids are involved.
It is better to define your boundaries in advance instead of reacting as a surprise with fear, anger, or passive acceptance of things that shouldn't be done to your dog.
People who don't respect or know boundaries are going to be magnetically drawn to situations and people who don't choose, set and enforce reasonable boundaries. You can't afford to smoke these people out by letting them transgress first, and then react afterwards. It is then too late, and the harm is already done.
For children, they have to be taught boundaries with the dog. They don't know boundaries instinctively, without instruction and experience. Boundaries must be modeled by the parents or dog owners, enumerated at an age appropriate manner, described, practiced and enforced. This concept is also going to be true of some adults. Many adults have little to no experience with dogs, and they need your help to know what to do and what not to do. If they don't know the boundaries you have chosen, you must assume they will cross those lines.
Therefore, what physical boundaries are you going to set? Who can touch your dog or enter your territory? When, where, how, and why? And what emotional boundaries are you going to set? What range of emotions are acceptable for people to evoke from your dog, and what ranges are unacceptable? And of those emotions and in what circumstances are these emotional states acceptable to be triggered and to what intensity?