Weak Security Practices:

[Mitu100@]

Insufficient multi-factor authentication (MFA), outdated security protocols, lack of employee training, or poor access management.
Notable Bitcoin Data Breaches (primarily affecting exchanges/services):
The history of cryptocurrency is unfortunately marked by numerous significant hacks and data breaches impacting exchanges and other services. Some of the most well-known include:

Mt. Gox (2014): One of the largest Bitcoin exchanges at the time, it suffered a series of hacks resulting in the loss of hundreds of millions of dollars worth of Bitcoin (around 740,000 BTC). This was primarily a theft of funds due to security vulnerabilities in the exchange's systems.
Coincheck (2018): Over $500 million in security and commodity brokers email list NEM (not Bitcoin, but a major crypto exchange hack) was stolen due to a hot wallet vulnerability.
Binance (2019): Hackers stole over $40 million in Bitcoin from Binance's hot wallet through a large-scale security breach that involved phishing, viruses, and other attacks.
KuCoin (2020): Over $280 million in various cryptocurrencies (including Bitcoin) was stolen.
DMM Bitcoin (May 2024): A significant hack where approximately $308 million worth of Bitcoin was stolen from the Japanese crypto exchange.