Why have my contacts disappeared?

[iMore Question]

I plugged the phone in to a usb plug in my rental car and they were gone

 

[kataran]

Re: i HAVE LOST MOST OF MY CONTACTS ON MY i PHONE, THEY JUST DISSAPERED

That seems impossible have you tried a Hard Reset of your device?

Have you backed up your device to iTunes or the cloud because you will be able to retrieve them if you did

 

[Ledsteplin]

Re: i HAVE LOST MOST OF MY CONTACTS ON MY i PHONE, THEY JUST DISSAPERED

Were they maybe Gmail contacts? This happened to me and I found they were Gmail contacts. I went to Settings > Mail, Contacts and Calendar > Gmail > toggled on contacts. They reappeared in contacts. This can work with others than Gmail.