A BBC investigation has put the spotlight on bail hostels, with undercover filming at two revealing that paedophiles associated with children.
Offenders are monitored but are allowed out
But just what part do these hostels play in the criminal justice system.
What are bail hostels supposed to do?
Bail hostels no longer just deal with those on bail. Now known as "approved premises", they have very few bailees. Another purpose is to provide "enhanced supervision" of offenders on community orders.
But representatives of those who work at the hostels say the majority of residents are now those who have been released from prison early. These offenders stay at the hostel as a halfway house measure to make sure they are ready to go back to the community and will not pose a danger.
Some within the criminal justice system have expressed reservations over the consequent lack of space for bailees and those on community orders.
What happens at the hostels?
Much of the activity at hostels is aimed at rehabilitating offenders and reacquainting them with basic life skills after many years in prison. Many of those released from prison might have individual programmes of courses, such as those aimed at drug users or sex offenders.
In addition to this, hostels run programmes based on the Home Office Reducing Re-Offending Action Plan which includes basic skills, literacy, health and accommodation advice, financial management, and employment advice.
The other aspect of hostel life is surveillance, including curfews and tailored monitoring of more dangerous offenders.
How many hostels are there?
There are 101 hostels in England and Wales, with between 12 and 40 residents in each, making a total population of about 2,000 people. Very few are purpose built - instead being residential conversions - and the vast majority are in towns and cities. There used to be hostels in rural areas, but this practice has been discontinued.
Who runs them? Is work already contracted out?
Of the 101 hostels, 12 are run by voluntary organisations who operate to the same standards and the same levels of training as those run by the Probation Service. One hostel is a joint venture between the prison and probation services.
Some hostels contract out night security to private firms, but the vast majority of staff at every hostel are professionals well-versed in issues to do with monitoring and rehabilitation. Staff in voluntary group hostels commonly work with seconded Probation Service staff and all hostels have a probation liaison officer.
How are paedophiles monitored?
Staffing varies between hostels, but there must be two on duty at any time, including overnight, and a staff to resident ratio of 1:5 is typical.
Martin Wargent, chief executive of the Probation Boards' Association, said the real issue was not why paedophiles could not be monitored all of every day, but the amount of serious offenders now in the system.
"When I was a hostel warden there were 2-3 dangerous offenders, staff could have a close eye on them. Now there might well be 30 dangerous offenders."