If you use the same password to log into more than one online service or social networking site, it may be time to change your login details.

Major companies such as Facebook and Netflix are scanning through login details revealed in previous data leaks from other sites to see whether their own users' credentials match.

If they find matching passwords, they are then asking users to reset their passwords in an attempt to increase their security.

Netflix have sent emails to many of their users, forcing them to change their passwords, who they have found to have matching credentials with other sites, such as LinkedIn, Tumblr and Myspace, from leaked data

MARK ZUCKERBERG IS HACKED This week it was reported that Facebook founder and CEO Mark Zuckerberg's Pinterest and Twitter accounts have been hacked. Saudi-based group OurMine claimed responsibility, using Zuckerberg's own accounts to post messages. The group claims it found his password 'dadada' in the recent leaks of the LinkedIn in password dump from 2012, in which usernames and passwords associated with more than 160 million accounts were compromised. Advertisement

Netflix, for example, sent emails to multiple users last week who used the same password for them as they did for LinkedIn, Tumblr and Myspace a few years ago.

The message read: 'We believe your Netflix account credentials may have been included in a recent release of email addresses and passwords from an older breach at another company,

'Just to be safe, we've reset your password as a precautionary measure'.

It then added that those who want to reset their passwords again should click on 'forgot your email or password'.

Netflix said it had taken the step because they know hackers will be using the passwords obtained from previous data leaks from other organisations to try and access people's profiles on multiple other third-party sites.

Netflix has developed a software called Scumblr that scans websites for content of interest to their organisation.

Facebook scoured the leaked credentials from the Adobe data leak in 2013 to see whether users were still using the same passwords across more than one site, in order to stop hackers from being able to access accounts

They have been using it to look through the breached data.

They said in a statement: 'Some Netflix members have received emails encouraging them to change their account passwords as a precautionary measure due to the recent disclosure of additional credentials from an older breach at another internet company,'

'Note that we are always engaged in these types of proactive security measures (leveraging Scumblr in addition to other mechanisms and data sources), not just in the case of major security breaches such as this one.

Facebook has also previously scanned through breached data to check for repeated credentials.

After the 2013 Adobe data leak that exposed tens of millions of user's credentials, Facebook scoured the information to flag up customers that had used the same leaked password for their site.

You will only be alerted if you use the same email for different sites included in the breaches.

Recently, details from users of Gmail, Hotmail and Yahoo were found to be hacked and traded in Russia's criminal underworld.

Details of 40 million Yahoo Mail users, 33 million Hotmail users and 24 million Gmail accounts were in the data being traded.