If you have a Yahoo email account, you’re not alone. The company is one of the largest free email account providers on the internet, which unfortunately means that when they suffer a data breach, it tends to impact a lot of users.

Back in 2012, Yahoo reported a data breach which they estimated impacted about 450,000 user accounts. It turns out that that number may have been a bit on the conservative side, however. Recently, a hacker going by the name of “peace_of_mind” has put a database up for sale on the Darknet containing a user id’s and passwords for a staggering 200 million accounts. Current best information says that this data came from the 2012 breach.

Of course, this isn’t the first high profile, large sized data breach we’ve seen surface in recent months. A Russian hacker group has claimed responsibility for massive breaches of LinkedIn, Tumblr, and other popular websites, with each of those breaches impacting more than a hundred million users, underscoring the dangers, and also underscoring just how far ahead the hackers are in terms of the ongoing data security battle.

From the perspective of the end user, the message couldn’t be any clearer. If you have and use a Yahoo email account, change your password immediately, in light of this latest information. If you tend to use the same password across multiple sites, discontinue that practice immediately, or risk having several of your accounts compromised, and possibly having your identity stolen.

At this point, these are not new warnings. Everyone should be well aware of the risks that bad password practices pose, but unfortunately, too many people have adopted the “it can never happen to me,” mindset. That works…right up until it doesn’t, at which point, it’s too late, of course.

Don’t delay. Change your password today, and get away from the habit of using the same password across multiple sites. You’ll be glad you did.