"The squirrel monkeys have managed to gain access to some of the taller trees in their enclosure and from there, have leapt into the higher branches of a tree in Regents Park," a London Zoo spokeswoman said.
They go on to say that the squirrel monkeys pose no threat, but then they mention this bit:
She said they were a very intelligent set of monkeys and staff had previously had to train them to stop stealing visitor's mobile phones.
Thievery and jailbreaking?! These critters are obviously immune to rehabilitation.
Update: As expected, Betty, the last of the bunch to still be roaming around, finally came back on her own.