Cloud products can have markedly different security so it’s hard to lump them all together. Larger Cloud providers generally have greater resources to apply to security than individuals or small organisations, so you can often enjoy very good security at an economy of scale. If you are considering Cloud storage on a daily basis there are a few elements to bear in mind e.g. internet speed required i.e. any increased costs, reliance on an external dependency, introduction of a single point of failure such as internet uplink, etc. There are data management considerations also, such as how and when you have access to your data, how privacy will be enforced, what happens to your data if the agreement is terminated e.g. exit strategy and business continuity planning, etc. RACGP has some good advice on Cloud at http://www.racgp.org.au/digital-business-kit/cloud-computing/