Some thoughts on the subject :
1) If i am a telephone company or whoever with the power to do so, and i start snooping around people (remote accessing of any of their data in any of their devices connected to any kind of network) , with the intention to keep those data on a file or to use it against them at a point, it would be counterproductive to alarm them in any way. Secrecy, not leaving traces and the element of surprise would be my utmost priority. Its of no use alarming/scaring someone, this makes them more suspicious and propably more carefull hence its counterproductive for anyone interested in cathing you redhanded.See? You already turned off your wi-fi! You used to have it on though, which brings us to the next point.
2) Sometimes people behave quite naively, whereas they know better: when people tend to "loosen up" and behave "casually" in such matters is that the "accidents" start to happen. This extents to many matters for example matters of privacy and online actions : People tend to get "over aquainted" with technology and with socialising through it that the phenomenon of "over-sharing" appears either by willingly providing data for almost public viewing, or unwillingly via storing sensitive material/information in places that can be accessed by third parties. Why put sensitive material in an iphone where a)propably material can be accessed by phone companies, they own the network, think about it for a moment b) has internet access and we all know that the most secure system is one that it OFFLINE ? Invest in a digital camera for sensitive material

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Think of it for a moment: how much information does your phone have about you? If i could access it ,what could i learn about you? If the responce is "almost everything" then rethink your course of action. Same goes about your computer. For example in this thread you did not even blur or distort the phote you used to give us an example. Now,everyone interested knows the face of your son, knows that you have pot plants (!), and if one has physical or remote access to your phone or to the network might even have more information such as your address ,other hobbies of you ,you wife's/gf face/phonenumber/name etc. Scary isnt it? And whats best, what takes the top of the cake? If i was someone trying to gather information about you (from stalker to anyone interested in having info on you) i wouldnt even have to go for the famous dumpster diving, following you around or trying social engineering to obtain info. All the information is given generously and happily by their owners...Ah, where are the good ol' days where stalkers and secret services had the actually fun of digging for information? Nowadays, everyone can lightheartedly act as an informant on themselves

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The above are rather easy to forget,Information is easy and fun to share!...After all ,we live in a world
full of friends, how could someone possibly harm us?
By the way, i am not saying that what you had was someone messing with your pics, propably it was a glitch. On the other hand, better safe than REALLY sorry! The above are not "textbook quality" paranoia and i am not fond of conspiracy theories at all : but they reamin well withing the realm of possibility and well within the power a phone company/ abilities of current technology.