Largest Data breaches of all times

Here are case studies of data breaches I came across learning about social media security:

• MySpace- MySpace was one of the largest social media networking site which suffered a massive data breach that came into light in 2016. Although the breach seemingly occured years earlier around 2013, it was reported when the stolen data was found being sold on darkweb. This impacted nearly 360 million user accounts leaking the usernames, passwords and email addresses. It was one of the largest data breaches of its time.
• Facebook- 540 million facebook records were accessible on a public server that included phone numbers, full names, locations, some email addresses, and other details from user profiles in April 2019. But facebook decided not to notify its customers whose personal information had been leaked until it was publicly available. They claimed to have secured the data but in September 2019 another 419 million accounts were found on a public server. But this was not the end. In December 2019, over 267 million Facebook users had their personal data exposed on the dark web, possibly for up to two weeks. By the time the media reported the breach, Facebook had already claimed to make security changes that supposedly fixed this vulnerability. However, in March 2020, another 42 million records were found online by the same criminal organisation. In 2021, yet another data breach was reported that exposed almost half a billion facebook accounts. Facebook acknowledged the leak but said it stemmed from a security problem in 2019 that their team has since fixed.
• Linkeden- In April 2021, a hacker who went by the alias 'TomLiner' claimed to have scraped data from Linkedin. Although Linkedin didnot agree saying the data must have been scraped from social media platforms and other networking sites. It was not until he posted 2 million linkedin accounts as a proof which were validated by Linkedin. After that he posted other 500 millions accounts for sale on dark web. The same hacker advertised advertised the information from around 700 million LinkedIn users on a darknet forum which was about 90% of Linkedin's total user database.
• Adobe- In October 2013, Adobe expericed a massive data breach that resulted in almost 38 million users having their accounts stolen. This included names, credentials, contact and details of their credit and debit cards. This happened due to Adobe's poor security policies and old encryption methods. It was also revealed that not login data but Adobe's source code from Adobe Acrobat and Reader, Photoshop, and ColdFusion was also stolen. Due to this breach, Adobe ended up paying $1.2 million as a legal fees and settlement to customer claims.
• Twitter- In 2020, some high-profile accounts like Barack Obama, Elon Musk started posting suspicious tweets encouraging people to donate Bitcoin under the pretense of doing good. This was also known as 2020 Twitter spear-phising attack. Hackers used social engineering to carry out a phone phishing attack on a few Twitter employees. Once these employees shared their login details, the hackers accessed Twitter's internal tools and went after employees with more access. This enabled the hackers to get higher-level login credentials.