I know that it's often convenient to have your personal files stored on your work computer, especially If you're like me and you spend a lot more time on your work computer than on your personal computer. I actually know some people whose only computer is their work laptop and they store all of their personal files on their work computer. Well, I'm here to tell you that storing sensitive personal data on your work computer is a VERY BAD idea. When it comes to your personal data that you don't want others to look at without your explicit consent, please do not store them on your work computer. The type of personal data that come to my mind are mostly items related to personal finances, such as electronic pay stubs, tax returns, and bank statements. But I'm sure there are many other sensitive personal data that belong in this category as well.
The biggest reason why storing your sensitive personal data on your work computer is a very bad idea is that you could lose access to your work computer in an instant--the most common scenario being if you were to get fired from your job. You may think that something like this could never happen to you, especially if you've been with your employer for a significant length of time and/or you've never been fired before; however it can happen to any of us, including those of us who are high performers (at least in our minds). When it comes to firing, it's common practice for employers to cut off all access to company property (including your work computer) at the exact moment that you are being informed of your termination, without any warning whatsoever. It's cruel, I know, but I'm certain that this is a practice that will continue for a very long time.
The scary part here is that once your employer has confiscated your work laptop filled with sensitive personal data, you have ZERO control over what they do with this data. As the senior-most technical person at the company, I've committed to making sure that former employees' laptops are wiped clean as soon as possible. I'm well aware of the fact that most people store a lot of non-work-related files on their work computers and I would hate for some really sensitive personal files to get into the hands of wrong people. It would be really easy, though, for me to think to myself that since these are laptops that no longer belong to anyone, I've got much better things to focus on. Even at companies where there are strict policies on wiping former employees' laptops as quickly as possible, mistakes do happen. Employees don't always follow policies and procedures. My guess is that a lot of companies don't even have any policies or procedures that deal with handling former employees' computers. I can think of at least one instance where a new employee was handed a laptop that had personal data of another employee who had recently left the company. Scary, I know.
I encourage you to spend an hour or two of your time and scan your work computer for any personal data you've got saved. Unlink your personal Dropbox account from your work computer. Look through your "My Documents" folder (especially the "Downloads" folder) and delete all files that aren't work-related. Stop your favorite note-taking app (such as Evernote or OneNote) on your work computer from syncing with your personal account (I need to still do this...). Go to your "Pictures" directory and delete all non-work-related pictures.
Be a little bit paranoid for a moment and ask yourself how you would feel if you were to be fired on the spot come this Monday morning and all of the files on your work laptop were to belong to your employer.