Well, if you are posting here, it is certainly publicly viewable and available. Just something to keep in perspective.
Use whatever service/site desired. No worries.
But there are people who browse imgurs main page, and if you post an image, then someone else might see it!
For example, if someone comes to this website to ask a question about a small burnt black spot on their power supply, (this is just an example) and they use their camera to take a picture of their PSU, and upload it to imgur, and upload it to their post, then someone might come across that picture while they are browsing imgur.