I think it will take a new amendment that declares the contents of people's minds immune to government investigation, and creates a provision for external memory devices that are considered part of people's minds. As technology progresses, humanity is evolving to be partly digital. I'm not saying we're cyborgs yet, but pretty close in the way we use our devices and the ways in which we communicate with other people, and we're only going to get closer and closer in the coming decades.
So what, when people do start replacing body parts, including parts of their brains, with technology, will the government try to claim they should be allowed access to the data stored on them? I'm very worried they will absolutely try to get their hands on that data, and even with a warrant I have a lot of problems with that.
Nearer-term, imagine the Apple Watch. Data is stored on it, some of it may be stored "in the cloud" or transmitted via networks to other devices you own. Some of this data is the sort of deeply personal and intimate data the government would likely be unable to get through traditional means. I don't imagine many judges would give the police a warrant to listen to somebody's heart beat, for example, but that data will be there on your Apple Watch, possibly transmitted by you to devices or individuals you've expressly authorized.
Don't think the police will ever want to get that data? What if you're suspected of murder, and they know you own an Apple Watch, but don't have any witnesses or physical evidence you were at the crime scene. If they could get heart rate data on you at the time of the murder, and your heart rate was elevated from the adrenaline and exertion required to stab somebody a bunch of times, I guarantee you the police would like to present that data as evidence in court.
I also guarantee you some big government agency is going to think up the idea of monitoring everybody's heart data constantly, in order to predict and solve crimes and terrorism without any other evidence. More sensors are coming, more personal data collection is coming, and governments and law enforcement agencies are going to want access.
We need protection from this future, the Founding Fathers had no way to predict. Sadly the 10th Amendment is weaker than ever these days, or a new amendment probably wouldn't be required.