https://github.com/code-423n4/2022-07-fractional/blob/8f2697ae727c60c93ea47276f8fa128369abfe51/src/modules/Buyout.sol#L207
Per the code of Buyout.end function, the buyout is successful if the vault holds more than 50% of the fractional tokens.
https://github.com/code-423n4/2022-07-fractional/blob/8f2697ae727c60c93ea47276f8fa128369abfe51/src/modules/Buyout.sol#L207
However, a large shareholder who owns 51% of the fractional tokens can send all his tokens to address(0), which effectively burns 51% of the fraction tokens.
In this case, the NFT held within the vault is locked forever. There is no way to retrieve the NFT because it is impossible for a buyout to be successful as the vault can never hold more than 50% percent of the fractional tokens even if all the existing fractional token holders sell their tokens to the vault since 51% of them have already been sent to address(0).
The NFT and its fractional tokens lose their utility entirely when this event happens. For example, for a fractional token, no one would be able to display it in galleries in the metaverse. Additionally, fractional tokens of a locked NFT will be deemed as worthless in the open market.
Consider an alternative buyout mechanism that is less reliant on the number of tokens being held by the vault to determine whether a buyout is successful or not.
