Search for online dating
A few years ago, image recognition on a large scale was restricted to law enforcement and corporate security. Free services like Tineye and Google Images will search billions of indexed images on the internet for identical or similar pictures.This isn’t necessarily traditional hash or metadata specific – cropping or resizing an image is not a foolproof way to defeat this (as I show in the screenshot below, where Tineye and Google correctly identified my profile selfie which is substantially cropped on social media).
You make a malicious person’s life significantly more difficult by simply locking down your social media profiles so that nobody except people you know personally can view them, or that the data that is publicly visible is not enough to provide the attacker an advantage.
Give some consideration to how much information you’re giving other users over time and as a whole.