The latest Yahoo data hack, revealed late last year, caused shockwaves through the cyber security community, especially since it had taken Yahoo quite some time to identify it even had a problem.

This latest big security breach dates back to 2013, yet December was the first it was heard of. Should people be worried?

Information for sale on the Dark Web

Data from more than one billion user accounts was stolen. Experts say the data has been up for sale on the Dark Web for a while, but now that the hack is in the public domain, this data is no longer as valuable.

>See also: Yahoo data leak: the biggest on record

Yahoo hack might affect Verizon deal

News of the hack affected Yahoo share trading, and it looks likely that it could have a large impact on the Verizon buy-out.

The company has been under the spotlight for months, with rumours circulating that it had been hacked. However, Yahoo only just admitted to the data breach in December, which has caused an avalanche of criticism from Yahoo users.

So, what other data hacks have caused a storm in recent years?

Cyber security in the spotlight

This is not the first time Yahoo has been in the spotlight for data security breaches. Sensitive data from over 500 million user accounts, including financial information, was hacked in 2014, but until recently, nobody outside of Yahoo had a clue.

>See also: Yahoo data breach exceeds 1 billion accounts

When the news broke in September, it was believed to be the world’s biggest hack. Not now, though. The latest Yahoo data breach exceeds the September hack.

Other major data breaches include:

• Democratic Party – Hilary Clinton’s presidential campaign never really recovered from the damaging email leaks that occurred when hackers (believed to be Russian) breached security on a network used by Mrs. Clinton.
• LinkedIn – 167 million LinkedIn accounts were hacked in 2016. It wasn’t long before encrypted information was available for sale on the Dark Web.
• eBay – eBay has also been hit by hackers, with 145 million user accounts affected.
• Bitcoin – Hackers broke into the BitFinex exchange in Hong Kong and stole more than $65 million of Bitcoin.
• Sony Pictures – in 2014, hackers leaked a ton of personal information from Sony Pictures, including emails and Social Security details for Sony employees, some of whom were very high profile. Many of the email exchanges were deeply embarrassing for Sony Pictures.

>See also: Verizon’s expansion: the future for the telecommunication industry?

• Home Depot – Hackers stole more than 50 million credit and debit card numbers in 2014. The security breach had taken place over a month, but as is common, the company didn’t disclose the data breach for two months.
• Anthem – The U.S. health insurance company was the victim of malicious hackers in 2014. Fraudsters stole confidential financial data and personal information from nearly 80 million users, some of whom were later targeted by scammers.

If there is one thing people can learn from the Yahoo hack, it’s that online data is never secure. Always change your online passwords regularly and don’t use the same password across multiple accounts.