In a series of court filings, Mr. Guzmán’s lawyers have complained on his behalf that from the moment he arrived at 10 South, he has been locked in his cell for 23 hours a day, except for lawyer and court visits, and has been denied all contact with his family and the media. The lawyers claim that he is the most closely guarded inmate in the United States and that the terms of his imprisonment have hindered his ability to prepare for trial. Not only have they asked Judge Brian M. Cogan of Federal District Court in Brooklyn to loosen the restrictions he faces; they have also asked that a researcher from Amnesty International be allowed inside 10 South to investigate conditions.

It is a strange turn of events that Mr. Guzmán, a serial prison escapee who stands accused of killing thousands during Mexico’s bloody drug wars, has claimed the moral high ground as a critic of the penal system. After all, he twice broke out of high-security correctional facilities in Mexico — first in a laundry cart and then by way of a mile-long tunnel dug by confederates into the shower of his cell. Given his history, federal prosecutors have defended the restrictions as a necessary measure, arguing that Mr. Guzmán retains “unparalleled connections” to his associates in the Sinaloa drug cartel — and has a “proven history” of murdering his enemies even while under lock and key.

Though his environment is forbidding, some of the grievances he has lodged with jail officials — there have been at least 11 of them as of last month — have been decidedly small-bore. In one motion, Mr. Guzmán’s lawyers claimed that the tap water had disturbed his throat, prompting him to ask for bottled water. They also said their client briefly feared that he was hearing voices, though the government contends that he was merely picking up the sounds of a radio being played nearby.

That said, the restrictions in 10 South are so severe that loneliness seems to motivate some inmates to break the unit’s rules. One of those inmates, Oussama Kassir, once greeted a fellow Muslim prisoner in Arabic while being escorted down the hall “in the clutch of two prison guards,” according to an affidavit filed by his lawyer. For that infraction, Mr. Kassir lost his telephone privileges for four months.