I forgot to mention above when talking about metadata, that when it comes to photos, there is another risk involved called EXIF data, this is another form of meta data specifically related to images and may not be properly removed by Metadata Anonymisation Toolkit mentioned before.
EXIF data stands for Exchangeable image file format and affects JPG, JPEF, TIF and WAV files. A photo taken with a GPS-enabled camera can reveal the exact location and time it was taken, and the unique ID number of the device – this is all done by default – often without the user’s knowledge.
In December 2012, anti-virus programmer John McAfee was arrested in Guatemala while fleeing from alleged persecution in Belize, which shares a border. Vice magazine had published an exclusive interview with McAfee “on the run” that included a photo of McAfee with a Vice reporter taken with a phone that had geotagged the image. The photo’s metadata included GPS coordinates locating McAfee in Guatemala, and he was captured two days later.
To avoid this, only take photos that use PNG because it does not store EXIF data. To check if your photo has any revealing EXIF data attached to it, check out this site.
or you can download a tool by doing a quick search online to see what EXIF data may be contained in your photos before you upload them. Be very careful with any files that you upload online, because you never know what type of harmful data could be attached in them. It helps to use Tails, but always consider everything you put online as a potential piece of evidence to be used against you and always prepare for the day the feds come to your door.