Quartz:

If you got an email from Dropbox asking you to reset your password earlier this week, it’s a good idea to do it. Nearly 70 million stolen Dropbox passwords are circulating online, according to Motherboard, which obtained the data. The file-sharing service has confirmed the passwords are linked to a breach that took place in 2012, although it said the theft only involved user email addresses at the time.

If you want to check whether your password’s floating around online, you can check at Have I Been Pwned. It’s safe to enter your email address there to check against the databases from well known security breaches it maintains. The site is run by Troy Hunter, a Microsoft security executive who performed an analysis of the Dropbox password cache and confirmed they’re authentic.

I used the Have I Been Pwned site to check several of my email addresses to check if they have been compromised. Sadly, some had been and I made changes ASAP.