A report is a presentation and analysis of findings and data from practical research, aimed at investigating, exploring and sharing specific information. Meanwhile, an essay seeks to answer a question based on research too, but through the writer's own point of view, to support his own conclusions.
Taking this into account, we may say that <em>annoying people on cell phones</em> is a topic more suitable for an essay.
The answer is if we want to be free, we must act.