What about, instead of "I have a boyfriend", tell them you are uncomfortable and would rather them stop talking/harassing/being around you? Of course, I might

What about, instead of "I have a boyfriend", tell them you are uncomfortable and would rather them stop talking/harassing/being around you? Of course, I might be minimizing and, in fact, the molester might not be a rapist but still a fully fledged harasser. Isn't there any security service around at these conferences? Is it absurd to hope they are trained to deal with such situations if need be?