Ramsey Yousef, the WTC bomber, has been in H Unit for 15 years. He has progressed to being an orderly. From his 2012 court decision:

Yousef has held a paid job as a range orderly for H Unit since October 8, 2013. In that capacity, he is responsible for maintaining the cleanliness of a housing range on which six H Unit inmates live. He sweeps, mops, and buffs the floors; cleans windows; and dusts. ADX staff supervise him visually; he works without physical restraints. He is permitted to talk to inmates while he is working. He works a minimum of 3-4 days each week for at least an hour per day; sometimes he works more days per week and works longer shifts. Thus, Yousef's orderly job gives him at least 4 hours of out-of-cell time per week.

H Unit inmates receive out-of-cell recreation every day. Sessions typically last 1.5 hours. They exercise alone in outdoor cages.

Yousef's lawyer said at a hearing that his client had not had human contact -- not even a handshake -- in 15 years. Not even with staff.

There are about 420 inmates at Supermax. There are around 55 inmates in the country with SAMS. There are 56 federal inmates sentenced to death, most of whom are at Terre Haute where they will be executed. Tsarnaev is likely to stay at Supermax until his appeals are over, unless he can work his way down to a USP -- High Security, which is probably impossible.

The Special Security Unit (H-Unit) houses inmates who have Special Administrative Measures (SAM), pursuant to 29 C.F.R. SS501.2 or 501.3. Prior to arrival in this unit, the unit team will review the SAM and reason(s) for placement at the ADX to determine assigned quarters. There is a three-phase program for inmates housed in “H Unit”. The types of privileges afforded to these inmates are determined by the phase.

Here's what Tsarnaev has to look forward to if he has good behavior in the H Unit and still has SAMS.

Phase One is a baseline phase of the program in which the inmate may be permitted two non-legal telephone calls per month; restricted access to art and hobby craft items; access to a restricted commissary list; and escorted shower time on their respective range three times a week.

In Phase Two, an inmate may be permitted three non-legal telephone calls per month; access to an expanded commissary list; access to an expanded art and hobby craft list; and unescorted shower time on their respective range five times weekly.

The advancement to Phase Three may be contingent upon modification being made to the inmate’s SAM. An inmate in this phase may be permitted four non-legal telephone calls per month; to consume a minimum of one meal on the range with up to three other inmates; continued access to the expanded art and hobby craft items; access to a further expanded commissary list; and out-of-cell recreation on the range with up to three other inmates.

According to BOP:

Every inmate housed in H-Unit has the opportunity to demonstrate he may be afforded additional privileges.

An inmate’s advancement to the next phase of the Program is a classification decision as to whether the inmate can function with additional privileges without; posing a risk to institutional security and good order; posing a risk to the safety of staff, inmates or others, including the inmates himself; and/or posing a risk to public safety.

Shoebomber Richard Reid is in general population at Supermax. So was El Chapo's former partner, Hector Palma-Salazar. After El Chapo escaped in 2001 (leaving him behind), Palma Salazar got extradited to the U.S. and agreed to a 16 year sentence. He didn't count on Supermax, but that's where they sent him -- based on crimes he was never charged with. According to pleadings and transcripts in his case, he was only charged with conspiracy to distribute more than 5 kilograms of cocaine (the actual amount was 390 kilograms but the agreed upon amount for sentencing was 50 kilograms.) He wasn't charged with being a cartel leader or murders, but that's what they used to send him to Supermax. Palma-Salazar may be one of the lucky ones. He has since made his way through the F, J and K units and is now at the USP in Florence and gets out in 2016. (He got credit for the years he spent locked up in a Mexican jail while awaiting extradition.)

Here's how he described the outdoor exercise cages in an affidavit in his court case:

Each recreation period is approximately one hour and sometimes up to two hours long. Ten of the recreation periods each month are outside in a cage that is approximately five feet by three feet.

There are five such cages with one person in each one. When a person is placed in the cell he is not allowed out to go to the bathroom to urinate or defecate. Consequently after two or three men precede a person to the cell it is very messy.

Placement in the H Unit is not considered punitive. It's considered a security management issue. As to numbers, according to BOP:

The ADX houses less than one-third of one percent of the BOP’s overall inmate population: 95 percent of the inmate population was transferred to the ADX from other facilities, while only 5 percent are direct court commitments.

So Tsarnaev, since he was a "direct sentence" to Florence, is one of 21 inmates in the country sent directly to Supermax rather than being transferred there for bad behavior or other reasons afterwards. (5% of 420 inmates). Put another way, he's in a group that comprises 5% of less than 1/3 of 1% of the 200,000 inmates in the federal system.

Here's how the transition to "better treatment" works, from an Affidavit by the Unit Manager for the General Population Units at ADX filed in Palma-Salazar's case. (I just copied the relevant pages and left out the parts about Palma Salazar.)

Also, "General Population" at ADX doesn't mean the same thing it does at other prisons. You are still alone in your single cell almost all day until you get to the very last stage, when you get to have a cellmate and eat your meals out of your cell.

According to Palma-Salazar, even in "F Unit" which is a general population unit, all classes and religious services were available only through watching the 10" black and white TV set in his tiny cell.

Here are the units:

The inmate population is housed at ADX in nine different maximum-security housing units, that are divided into six security levels listed from the most secure and restrictive to the least restrictive.

• The Control Unit (for dangerous and disruptive inmates)
• The Special Housing Unit ("SHU") (a disciplinary unit, aka "the Hole"
• Special Security Unit ("H" Unit) for terrorists and extreme national security risks and the like
• General Population Units ("Delta," "Echo," "Fox," and "Golf" Units)
• Intermediate Unit/Transitional Units ("Joker" Unit and "Kilo" Unit) which houses prisoners entered into the "Step-Down Program" which they can earn their way out of ADX.

And the worst of the worst:

• "Range 13," an ultra secure and isolated four-cell wing of the SHU.

There is at least one other inmate with a death sentence and SAMS at ADX -- Kaboni Savage, the Philadelphia "drug kingpin" sentenced to death for killing 13 people, including the family of a protected witness who was going to testify against him. He was serving a 30 year sentence when he ordered the murders of 7 of the victims.

Inmates in the H Unit have gone on hunger strikes several times. Since the H Unit is not a disciplinary unit, maybe they should modify the commissary list and at least let them have ice cream. Of course, how would they get it before it melts, since they can't leave their cells to go to the commissary, the commissary items must be delivered to them? How about a golf cart with a freezer and speakers playing the universally understood ice cream man's truck tune as it makes it way through the cell corridor?