This lot currently auctioned on ebay is not actually a dangerous listing, as the seller states they are modern replicas:
Roman republican anonymous sextans:
Sicily, Mamertini AE Unit
Sicily Kamarina CNS 3
However they could cheat some naive collectors in the future if some scammer should buy the lot and re-list the coins as genuine, in particular the sextans and the Kamarina owl are not so obvious fakes, and also this listing by CNG raises some questions, as it is not clear whether the host coin or another clone.