You mean like being rendered into a canvas to get a high-entropy fingerprint of your device?
1. https://security.stackexchange.com/questions/91347/how-can-a...
2. https://threatpost.com/of-truetype-font-vulnerabilities-and-...
3. https://googleprojectzero.blogspot.com/2015/07/one-font-vuln...
You mean like being rendered into a canvas to get a high-entropy fingerprint of your device?