Wendy Zamora has written an article in the Malware Bytes web site about the security and reliability of storing your files in cloud-based file storage services. I recommend the article for reading by anyone who is not comfortable with using cloud services.
I agree with most everything that Wendy wrote although I would expand on one of her statements: ““Yes, your data is relatively safe in the cloud—likely much more so than on your own hard drive.”
The phrase “relatively safe” needs a bit more detail, in my opinion. If you simply copy your files to the cloud “as is” without modification, your files are PROBABLY safe from hackers but not guaranteed. However, even that small risk is easy to neutralize to make everything 100% secure.
I encrypt my more sensitive data before sending it to the cloud. That way, nobody can read my files, not even the ones stored on my home computer’s hard drive or on the laptop’s disk drive. Today’s industrial-grade encryption is impossible to decode without knowledge of the encryption key unless someone has a super computer and a few hundred years available to decrypt the information. When copied to the cloud, encrypted files remain encrypted.
The US military, the State Department, the FBI, the CIA, the White House, the Federal Reserve Bank, the various stock exchanges and stock brokers, and many others use encryption to keep their information private. I figure if it is good enough for them, it’s also good enough for me.
I fully trust a cloud service when I encrypt my data first. See my earlier article at https://goo.gl/jW9T2Y for one free and secure method of encrypting your files while still on your on hard drive. It is the method I use.
You can read Wendy Zamora’s article at https://goo.gl/4AC2VO.