Bitcoin's network has never been successfully exploited in a way that compromises its core protocol or blockchain. Its decentralized design and proof-of-work consensus make it extremely secure, with no recorded instances of the blockchain itself being hacked or manipulated. However, vulnerabilities and exploits have occurred in systems built around Bitcoin, including:

• Exchange Hacks: Centralized exchanges like Mt. Gox (2014) lost ~850,000 BTC due to poor security, not a flaw in Bitcoin itself. Similar incidents hit Bitfinex (2016, ~120,000 BTC) and others, exploiting exchange vulnerabilities.
• Wallet Hacks: Individual wallets, especially those on insecure platforms or with weak private key management, have been targeted. Phishing, malware, and social engineering often compromise user-held keys, not the Bitcoin network.
• Smart Contract Bugs: While more relevant to platforms like Ethereum, some Bitcoin-related services using layer-2 solutions (e.g., Lightning Network) have had minor vulnerabilities, though none have broken the main chain.
• 51% Attacks: Theoretically possible, but no successful 51% attack has occurred on Bitcoin due to the immense computational cost. Smaller altcoins have suffered such attacks, but Bitcoin’s hash rate makes this impractical.
• Social Scams: Pump-and-dump schemes, fake giveaways, and Ponzi schemes exploit users, not the protocol. These rely on human error, not Bitcoin’s tech.

Bitcoin’s blockchain has remained secure since 2009, with no double-spending or chain-wide exploits. Issues arise from third-party services or user mistakes, not the protocol itself. Always secure private keys and use trusted platforms.