There are a number of rights which are curtailed when in custody – whether pre-trial or as part of a sentence – but even under the appalling incarceration standards in the USA, the right to free speech is not something which is substantially limited while in custody, barring some very particular circumstances.

A defendant in jail awaiting trial has not, by definition, been convicted of any wrongdoing. So for pre-trial detention – where the purpose is to assure that the defendant won’t skip court – the only cognizable reason to curtail the defendant’s speech (either by mail, phone, or in-person) would be for jailhouse security reasons, as noted by various court rulings. The ACLU has litigated cases where prisons – ie post-conviction detention – violation the prisoners’ rights, so no doubt that pre-trial defendants in a jail would preserve more rights.

An example where free speech continued even while serving a sentence is when the Menendez Brothers gave a phone interview from a California prison, as part of a new documentary on the 1989 murders they were convicted of, now under scrutiny.

On the flip side, there are times when a defendant must have some speech curtailed prior to trial, even if they’re not in jail. Sam Bankman-Fried comes to mind, who was ordered pre-trial to not communicate with employees of his exchange (unless all lawyers are present) as the judge agreed with prosecutors that he could try to manipulate them into lying to the feds. At the time, he wasn’t in jail, but rather was at home under house arrest.

What would be outrageous in that case was if the order on Bankman-Fried was more sweeping, such as being restricted from talking about his own case, for which he has a First Amendment right to do so.

Appropriately, the First Amendment rights must be jealously guarded, even for people we might not agree with, precisely because it also protects people we do agree with.