IPad hacked via WIFI?

Question

Folks, my mom uses a 3rd gen iPad, often in public WIFI hotspots, such as the Lightrail or at her place of work (The Tech) in San Jose.
Yesterday, she found that her iPad had a different background image; one that she didn't photograph and one that she certainly didn't put there herself. Coincidence or not, on that trip back home, she was asked by a fellow Lightrail rider what she thought of her iPad and that he had tons of great photos on his.
I suggested that perhaps someone at work thought it would be funny to change the background picture and somehow got hold of her iPad while she was manning a station, but she insists that the device is always within reach, so that wouldn't have been possible.
I guess this is something I haven't thought of before, because I use a Macbook on the road (which has a firewall), but: how vulnerable is an iPad on a public Wifi hotspot? Does the thing have some sort of firewall protection or is it "wide open" and ready to accept commands from someone that has it's IP on that network?
Thank

Answer 1

Might this image have been one of the Apple-provided ones? It's certainly possible that the iPad would have lost that setting for some reason - perhaps, for example, the previous background image was a photo in her photo stream, and it was removed from there - and reverted to another image.
It's very unlikely, nearly to the point of impossibility, that someone remotely hacked her iPad. There is no currently known technique for doing that. Hacking an iPad isn't that hard, but you need physical access to the iPad to do it.
One thing that can sometimes look like hacking is if someone has gained access to the Apple ID associated with the iPad. This can result in changes being made remotely, even though there's really no direct access to the iPad. Although there's no way to change the background image remotely on an iPad using access to the Apple ID, it could explain where the previous background image went, if it's no longer present on the iPad. If you suspect this could be the case, have your mom change her Apple ID password immediately.