The plaintiffs, some of whom were injured, and others the estate of those killed in the attacks, proved up their case by showing that many of the perpetrators and planners has been employees of the PA, and that it had made payments to the terrorists, and families of the suicide bombers.
Collection of a judgment against the PA & PLO may be problematic, however. The PA is insolvent, and riddled with debt at present; the Government of Israel is presently withholding customs revenue, due to the actions of the PA, in joining international bodies, and withdrawing from settlement talks. Local banks in the Territories have declined to give the PA any temporary funding, to cover its budget. The case does have significance, though for compliance.
For compliance officers, though the Palestinian Authority is not a designated terrorist organization, this decision should result in your taking a closer look at the senior Palestinian leaders who were known to be involved in the terrorist financing of the attacks, and it certainly raises Country Risk levels for the Palestinian Territory located in the West Bank, which is already extremely high.
Note that most of them hold Jordanian, Egyptian, or other Middle Eastern passports; some even have more than one passport, as well as EU travel documents. The fact that billions of dollars, donated specifically to help the Palestinian people, have disappeared into the hands of corrupt Palestinian PEPs, means that it is foolish to even consider accepting them as clients. The late Yassir Arafat is rumored to have taken billions in donated aid money, and he deliberately ignored corruption by his inner circle and supporters.