Almost 30 percent of smartphone users leave their device unlocked as they do not believe they have any data worth protecting, a survey conducted by the University of California Berkeley and Google revealed.
About a third of people with smartphones find locking their phones too much of a hassle and one-fourth of users believe no one would care about what is on their phone.
The researchers asked smartphone owners detailed questions and also accessed data from a Google survey of more than 2,500 smartphone users, who answered questions related to security locks on their phones.
They found that many failed to see the difference between security and privacy.
Most of them locked their phones so that friends and family did not snoop on their devices.
Users also did not realise that they had sensitive information stored on the phone and the consequences if it were stolen, media reports said.
Of those who chose not to lock their phones, many simply lacked the desire to do so in the first place.
The most common explanation was lack of motivation as they simply had not gotten around to setting it up, but were not averse to it, the survey noted.
Access to emails without passwords on smartphones was considered to be another lapse.
Within their emails, three-quarters had their home addresses and half of them their birth dates.
Also, 26 percent had their bank account numbers and 16 percent had stored their credit card numbers in their emails, the findings showed.