  The advent of blockchain technology and its adoption across various sectors
have raised critical discussions about the need for regulatory mechanisms to
ensure consumer protection, maintain financial stability, and address privacy
concerns without compromising the foundational principles of decentralization
and immutability inherent in blockchain platforms. We examine the existing
mechanisms for smart contract termination across several major blockchain
platforms, including Ethereum, BNB Smart Chain, Cardano, Solana, Hyperledger
Fabric, Corda, IOTA, Apotos, and Sui. We assess the compatibility of these
mechanisms with the requirements of the EU Data Act, focusing on aspects such
as consumer protection, error correction, and regulatory compliance. Our
analysis reveals a diverse landscape of approaches, from immutable smart
contracts with built-in termination conditions to upgradable smart contracts
that allow for post-deployment modifications. We discuss the challenges
associated with implementing the so-called smart contract "kill switches," such
as the balance between enabling regulatory compliance and preserving the
decentralized ethos, the technical feasibility of such mechanisms, and the
implications for security and trust in the ecosystem.
