There are definitely several disturbing pieces of information we learn about Jonas's community in the early chapters of Lois Lowry's The Giver.
One disturbing aspect is the understanding that outsiders are completely unwelcome. We see this aspect illustrated through the jet that mistakenly flies over the community. The community apparently frequently sees cargo planes land to bring supplies but never jets. As soon as the jet is seen, the people of the community are instructed via loudspeaker to abandon their bicycles and take cover in the nearest building. Soon, it is explained the pilot had gone off course; it is further announced, "NEEDLESS TO SAY, HE WILL BE RELEASED" (p. 2). Release, we learn, is a "terrible punishment" in which individuals are exiled from the community and left to fend for themselves, which as far as the community knows, essentially leads to being starved to death.
Another troubling aspect we learn about the community is its elders have such control over the individuals of the community that they even control word choices. For example, we are told of the story in which Jonas's friend Asher apologizes for arriving late to class one day by saying he had felt "distraught" watching the fishermen separate the salmon and is commanded instead to use the word "distracted." However, if Asher had been contemplating that separating salmon meant life or death for the salmon, then feeling "distraught" should certainly be a justifiable feeling he is entitled to.