If i was to use a service like Mazuma to get some money for my old mobile, i would definitely follow any instructions to delete texts / contacts / etc.

However, i always worry that such data can be recovered from a phone even if seemingly deleted from the device, and following on from that I have concerns about the motivations (e.g. identity theft) of some of the people who can end up buying used phones from companies like Mazuma.

Am i being paranoid?

Yes

As long as you do a factory reset you should be safe, it will wipe all data.

I know on old hard drives the data would still be there so you have to use some eraser program. But I'm pretty sure for mobile devices since they use a form of flash memory that this isn't the case. Can anyone else verify / deny this?

you can recover data from flash memory, but the chances of finding anything usefull ie address , card numbers ect is very very low , it wouldnt be worth the agro, there is much easyer ways to get that

http://www.theregister.co.uk/2011/03...bayed_mobiles/

"A total of 247 pieces of data were recovered from a total 19 of the 35 mobile phones and 27 of the 50 SIM cards. Data left on these handsets and communication devices included many photos (including pornographic images), bank details, login details for social networking sites and PIN numbers as well as private texts and emails."

Yeah, but I bet you anything the ones they recovered data from didn't do a factory reset.

Sellers still forget to take out SD cards and SIMs that continue to hold data beyond a factory reset.

even a factory reset menu on my phone didn't delete half the stuff, had to type in some uber-code to completely wipe the thing.

That article isn't talking about recycling handsets, its discussing handsets which have been sold second hand (eg ebay etc )

http://www.telegraph.co.uk/news/cele...lackberry.html