Is it illegal for someone to take a picture of you without asking you? Thank you.

It is not a crime to take a photo of someone at work. However depending on what happens next, if anyhthing, there could be civil liability for using the photo for a commercial purpose without your consent, invading your privacy, or portraying you in a false light. The proper remedy would be to complain to your supervisor at work or the HR department if applicable.

I agree with the previous answer that a co-worker's single cell phone photo of you isn't illegal, or an invasion of your privacy, since cell phones with cameras are ubiquitous in our society, and you don't have a reasonable expectation that your image won't be put on a cell phone photograph in the workplace. If the co-worker doesn't stop taking photos of you, or if she attempts to take photos of you that are altered in some unflattering or false way or show you in a "false light, then you might have a claim. Since those things don't appear to be happening, you should try to get along with your co-worker, ignore this very small slight to your sensitivity about being photographed, and don't look for problems that aren't there. Disclaimer: Please note that this answer does not constitute legal advice, and should not be relied on, since each state has different laws, each situation is fact specific, and it is impossible to evaluate a legal problem without a comprehensive consultation and review of all the facts and documents at issue. This answer does not create an attorney-client relationship.