"Indeterminate sentences were introduced on the understanding that rehabilitative treatment would be made available to those prisoners concerned.
But the ruling published on Tuesday said the court found the "considerable delays in the applicants making any progress in their sentences had been the result of lack of resources, planning and realistic consideration of the impact of the sentencing scheme introduced in 2005".
The European judges note that the problems with IPP prisoners were the subject of "universal criticism" in the British courts. The ruling said the three inmates had been left in privately run local prisons for two and half years, where there had been few, if any, rehabilitation programmes.
"The stark consequence of the failure to make available the necessary resources was that the applicants had no realistic chance of making objective progress towards a real reduction or elimination of the risk they posed by the time their tariff periods expired," says the ruling.
"Moreover, once the applicants' tariff had expired, their detention had been justified solely on the grounds of the risk they had posed to the public and the need for access to rehabilitative treatment at that stage became all the more pressing"."
The UK coalition government seems to have agreed with this assessment before the Court made its ruling, since it has announced the end to indeterminate sentencing. However:
"The new justice secretary, Chris Grayling, told MPs he was disappointed by the judgment, and intended to appeal against it. He said: "It is not an area where I welcome the court seeking to make rulings.""
I'd like to hear what areas he thinks a human rights court should be making rulings, if not in the area of the right to liberty. It's also striking that the government is planning to appeal a ruling against a policy with which it no longer agrees - perhaps Conservative ministers enjoy the feeling that they could bring in sentences that effectively lock people up for longer than their sentencing without any hope of release!
In any case ensuring that the criminal justice system is fair and transparent - in other words, that it complies with the rule of law - is a basic part of human rights law, and it's exactly in these types of circumstances that the court should be intervening against the arbitrary actions of the state.