Quick note to self (and anyone else who is interested). You can bulk remove metadata from photos using gThumb on Fedora Linux (and probably all gnome based Linuxes and others besides)
- Navigate to a folder with all the images in
- Select all (control+a)
- Right click on the selection
- Choose open with gThumb
- In gThumb again, select all
- Click the spanner icon top right
- Choose delete meta data
- You can check it works by going back to the original file, right clicking an image and seeing what meta data displayed still