If you’re a regular internet user the Personal Data Storage paradigm won’t move your data from the cloud to your personal computer. Most people will still rely on an institutional cloud service, but instead of data-banking with a shareholder-controlled corporation people’s data can be entrusted to the equivalent of member-owned credit unions for data storage.
Sadly, if it is in the cloud, it can get hacked far more easily than on your local. But neither is really safe. And very few people can stomach what they would have to do to improve thier odds.