I'm not a big phone user, and I have a Galaxy Ace thats pretty old now, so I'm looking at a second hand / pre-owned Samsung Galaxy S4. The question is, that buying second hand / used how can I be sure there isn't any hidden spyware installed on it, that would send my passwords, messages, bank details etc to some third party?
If the answer is 'I cant...' thats fair enough.
Thanks
