One of the main points of concern following the recent Bitcoin Cash hard fork and subsequent network split is the lack of replay protection. In theory, the SV team would be able to reorganize the ABC chain if they ever intended to do something nefarious. That is no longer a possibility, as the ABC developers introduced a checkpointing system. While that is a solid decision, it has also received a lot of flack over the past few days.
When two “versions” of the same blockchain exist, an interesting situation is created. Miners and developers on each chain can exert full control over a competing chain. This is very unlikely to ever happen, but one can never dismiss such a possibility in the slightest. This uneasy situation can be quite problematic for wallet providers and exchanges, as they risk falling victim to “fraud” in the cryptocurrency world.