Whether or not they are unrecoverable has yet to be seen. The blockchain is public, if something can be identified as stolen, there may be a strong disincentive

Whether or not they are unrecoverable has yet to be seen. The blockchain is public, if something can be identified as stolen, there may be a strong disincentive to accept bitcoins which have that mark. If all stolen mobile phones had giant signs attached saying "stolen", the market for those phones would be greatly reduced. Bitcoin's anonymity and extra legal nature have been greatly exaggerated.