Many folks already know their digital cameras capture info about the images they take; aperture, shutter speed, lens used, etc. Smartphones also may be including the location latitude and longitude if the GPS on the smartphone is active. There are addons available for web browsers that make this readable by simply rolling the mouse over the image displayed in the browser. I don't care about the photo data, if anyone might be interested in the shutter speed, etc, I don't care if they can read that. However I do draw the line at GPS info. If it matters to you either turn the GPS off or strip the EXIF location data before uploading the images.
Windows has the ability to strip EXIF info built in. Select a photo or group of photos in Windows Explorer, right-click and hit Properties. Under the Details tab, you'll find a link (near the bottom of the window) that says "Remove Properties and Personal Information". Click that, and hit OK in the window that comes up. You'll have a copy of each photo in that same folder. The copied photos will be the one with clean data. You can also customize to remove data selectively and leave info you might want.
I also found freeware software available to do this. Also later versions of Photoshop has the ability to remove personal data when files are saved using the "save for web" option.