Is this somehow fundamentally different from having memories?
Because I thought about it, and decided that personally I do - with one important condition, though. I do because my memories are not as great as I would like them to be, and they decline with stress and age. If a machine can supplement that in the same way my glasses supplement my vision, or my friend's hearing aid supplements his hearing - that'd be nice. That's why we have technology in the first place, to improve our lives, right?
But, as I said, there is an important condition. Today, what's in my head stays in there, and is only directly available to me. The machine-assisted memory aid must provide the same guarantees. If any information leaves the device without my direct instruction - that's a hard "no". If someone with physical access to the device can extract the information without a lot of effort - that's also a hard "no". If someone can too easily impersonate myself to the device and improperly gain access - that's another "no". Maybe there are a few more criteria, but I hope you got the overall idea.
If a product passes those criteria, then it - by design - cannot violate others' privacy - no more than I can do myself. And then - yeah - I want it, wish there'd be something like that.