daf bit: Bava Kama 67

[cellio]

The mishna teaches: one who steals from a thief (what has already been stolen) need not pay double for the theft (that is, paying both the owner and the person he stole from). Rav taught in the g'mara: this applies only in the case where the original owner has not yet renounced (given up on) the goods. (This means the first thief has no claim of damage when he is stolen from.) Rabbi Sheshet, showing that discussion in the g'mara can sometimes run toward the lively, asserts that Rav must have been half-asleep in bed when he said that. (67b)

(The ensuing discussion is somewhat confusing to me, so I don't know who won that argument in the end.)

Comments

[zevabe.livejournal.com]

To clarify further: If the original owner (A) abandons hope of getting the stuff back, it now belongs to the thief (B). Another thief (C) would thus owe the usual penalty according to Rav. Rav Sheshet (check this but I think it is Rav not Rabbi, with ensuing implications for Babylonian or Israeli) would presumably disagree and say that C need only pay once.

If A expects to get his goods back (eg he hired a really good private eye), C would owe only once according to all, because the property does not belong to B (unless he did one of the other things which cause a thief to own his stolen goods, such as converting its useage: wool into a sweater for example).