A bit of insight about what caused this for Hedera Monkey collections. It's definitely not related to Hashpack or SentX:
The cause was old staking contracts from the HMNKY staking platform, along with an older Hash Horses contract that had the same flaw. When you stake, your wallet gives the contract permission to move your NFTs, and that permission stays in place after you unstake.
The HMNKY staking contracts, and the Hash Horses contract, had a flaw in a public function called transferFromNFT(token, from, to, serial). The function moves one NFT from one wallet to another using the contract's allowance, but it didn't limit who could call it. That meant any account could use it to move NFTs whose owners had approved the contract.
Today, one account used it to move 52 NFTs out of 15 holders' wallets without anyone signing anything, then sold 29 of them into open bids on SentX. The NFTs weren't taken through SentX, Hashpack or through anyone's wallet.
Trading on Hedera Monkeys, Banana Peel HMNKY, Early Monkeys, HashPack x HMNKY and Hash Horses is paused on SentX temporarily:
If you have ever staked HMNKY or Hash Horses NFTs on their paltform, revoke the NFT allowances you gave these contracts from your wallet, even if you unstaked long ago:
• 0.0.3927013 (HMNKY staking)
• 0.0.6028958 (HMNKY staking v2)
• 0.0.1973063 (Hash Horses)