Steve Harris is trying to delete images in the Image Capture app, but a lock icon appears on photos. He wonders how to proceed.
The most common reason for this is that you’ve mounted a memory card through a Mac’s SD Card slot or an external card reader, but the card’s tiny lock switch has been flipped on. I have never intentionally used the lock switch, which is designed to prevent accidentally overwriting images and video as a physical, on-demand read-only setting.
Eject the card, then flip the switch to the unlocked position, then mount again. The locks should be gone. If they remain, the card may be damaged. SD cards are tiny computers that manage the wear pattern on what is effectively an SSD. If the on-board computer determines it can’t write data, the only indication would be these locks in Image Capture.
You can copy all the media off and try reformatting in a camera, but if that fails, the card has gone bad.

Lock icons should only appear when the media, usually an SD card, is set to read-only.
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