According to a global survey of 3,000 consumers conducted by McAfee and One Poll, a third of respondents don't bother to protect their mobile phone or tablet with a PIN or password.
The survey revealed that most mobile device users remain unaware of potential breaches to their privacy, as smartphones and tablet devices are increasingly becoming attractive targets for cybercriminals.
According to the survey, the majority of consumers in the UK and Germany stick with the first PIN which is given to them while in France and America consumers are more likely to use a personalised number.
The survey suggests that more than one in ten use the same PIN across multiple devices and accounts, which McAfee said is a worrying finding.
In the survey, 55% of all respondents admitted that they have shared their password or PIN with others.
About 61% of tablets users said that they have shared their PIN with others while 49% of mobiles users said they have shared their PIN, which indicates that consumers value the data on their phone more than that on their tablet, the survey added.
According to the survey, only one in five respondents have backed up the data on their phone and tablet in case it's lost or stolen.
The survey found that 15% save password information on their phone, most commonly in the 'notes' section, meaning that if their phone falls into the wrong hands they risk opening up all sorts of personal information like bank details and online store logins.
Half of respondents in the survey said they allow their children access to their mobile or tablet while one in six admit that their child knows their PIN or password.
The survey found that 10% are even happy to share their password to iTunes or other app purchasing sites to allow their kids to buy apps.
McAfee CTO for EMEA Raj Samani said: "It's clear that consumers are forgetting exactly how much valuable information is stored on their mobile or tablet. These devices can contain personal data like bank details and addresses, so it's crucial that people take the same care they would with their wallet or computer."
"Failing to set a PIN or password is like leaving your front door open: Would you be surprised if you came home to find your PC missing? Our McAfee Consumer Trends Report shows that mobile devices are becoming increasingly attractive to cybercriminals as they look for new ways to steal digital identities and commit fraud."