I have documents stored on 'the cloud' so I can access from anywhere with any device. No personal info within the doc beond a name, phone and email address which can be found anywhere. As someone else mentioned, the 'cloud' is simply a server housed somewhere here on earth. While I am not particularly a 'conspiracy theorist' I do next to nothing online..no banking, little shopping, etc. I do not believe today's hackers care one iota about our personal pc's...they get a bigger bang hacking our banks, department stores, cc companies. Even if we don't do anything online personally our info is housed by these companies and is at risk regardless.
Back to the question of stori g photos on the cloud...I would probably get an external hard drive and keep it local but would not have an issue using the cloud either. I use onedrive.com and do not share or make anything public.