At one point, the rottweiler was considered to be the most dangerous dog breed out there, and if you saw one on the street, most people would not risk walking right by them. Considering their impressive size—they can reach up to 25 inches tall and weigh around 120 pounds—they can easily instill fear in people.
What makes them dangerous is the fact that they have quite a temperament at times, and due to their size, they can easily pose a threat to people. Not to mention, people have been using them as guard dogs and even attack dogs in some cases, so their reputation precedes them.
Despite this, you should not consider them just a threat to you: they are known to be loyal, extremely friendly, and protective of their families, which means that they will not pose any threat to you if you add one to your family. If not trained properly, they can pose a threat to people outside of their family and known people, as their first instinct is to protect their owners, and that’s when they can get pretty aggressive.