[21.1.1-3.] AT this time also it happened that the embassy, which the Lacedaemonians had sent to Rome, returned disappointed. The subject of their mission was the hostages and the villages. As to the villages the Senate answered that they would give instructions to envoys sent by themselves; and as to the hostages they desired to consider further. But as to the exiles of past times, they said that they wondered why they were not recalled, now that Sparta had been freed from her tyrants.  At the same period the Senate dealt with the ambassadors from Philip. They had come to set forth the loyalty and zeal of the king, which he had shown to the Romans in the war against Antiochus. On hearing what the envoys had to say, the Senate released the king's son Demetrius from his position as hostage at once, and promised that they would also remit part of the yearly indemnity, if he kept faith with Rome in future. The Senate likewise released the Lacedaemonian hostages, except Armenas, son of Nabis; who subsequently fell ill and died.  Directly the news of the victory at sea reached Rome, the Senate first decreed a public supplicatio for nine days,—which means a public and universal holiday, accompanied by the sacrifice of thank offerings to the gods for the happy success,—and next gave audience to the envoys from Aetolia and Manius Acilius.
When both parties had pleaded their cause at some length, the Senate decreed to offer the Aetolians the alternative of committing their when cause unconditionally to the arbitration of the Senate, or of paying a thousand talents down and making an offensive and defensive alliance with Rome. But on the Aetolians desiring the Senate to state definitely on what points they were to submit to such arbitration, the Senate refused to define them. Accordingly the war with the Aetolians went on.
[21.3.3-4.] After listening to him the senate at once set free his son Demetrius, who was their hostage, and also promised to relieve him of some of the payments due, if he kept his faith with them under present circumstances. 
hey also set free the Lacedaemonian hostages except Armenas, the son of Nabis, who soon after this sickened and died.
[21.11.9-10]In Greece itself they adduced the cases of Philip and Nabis. As for Philip, after they had crushed him in war and tied his hands by imposing hostages and tribute on him, no sooner had they received from him a slight proof of his goodwill than they had restored to him his son and the other young men who were held as hostages together with Demetrius; they had remitted the tribute and given him back many of the cities taken in the war.  And while they could have utterly annihilated Nabis, they had not done so, but spare him, although he was a tyrant, on receipt of the usual pledges.