Bob requests a lawyer to be present while the police interview him after being arrested. The police just laugh.
The Sixth Amendment to the US Constitution guarantees assistance of counsel for the accused in all criminal prosecutions. The Fifth Amendment protects a person from being forced to self-incriminate. Taken together, in Miranda v. Arizona, the Supreme Court interpreted this to mean that police cannot continue interrogation after you have requested an attorney. Laughter is actually not a violation of your rights, the violation would come from continuing to interrogate you, or in prohibiting you from contacting your attorney or not providing an attorney if you cannot afford one (via the public defender's office).