Can someone use my old phone and hack into my new phone?

[Android Central Question]

I took my sim card out of my old phone and used it in my new one. My son used my old one for you tube and lost it. Recently, my new phone has been acting strange. Can someone hack my new phone and have access to It after finding my old one with no sim card?

 

[belodion]

Did you remove your account from the old phone, and factory reset it? Does it have a screen lock?

 

[Mooncatt]

It's unlikely they could hack your phone directly. If they somehow got into the old phone and figured out your various login credentials, they could effectively steal your identity without any interaction with the new phone.

If you register an account here, you can reply to this thread and let us know what you are seeing on your phone that is "acting strange." Usually these sorts of issues turn out to be nothing more than a misunderstanding of how Android works, or some sort of hardware or software bug, and we can help you sort it out.