diff --git a/Appendix-C:-Test-Sites.md b/Appendix-C:-Test-Sites.md
index 18de1f0..c12008d 100644
--- a/Appendix-C:-Test-Sites.md
+++ b/Appendix-C:-Test-Sites.md
@@ -63,6 +63,7 @@ If you would like to submit a test page to be added to this list, please post th
 - [Evercookie](https://samy.pl/evercookie/) - **h**ttps://samy.pl/evercookie/
 - [Firefox Extensions](http://thehackerblog.com/addon_scanner/) - **h**ttp://thehackerblog.com/addon_scanner/
 - [localStorage](http://www.filldisk.com/) - **h**ttp://www.filldisk.com/
+   * Firefox is immune to this hackery
 - [HSTS Supercookie](http://www.radicalresearch.co.uk/lab/hstssupercookies) - **h**ttp://www.radicalresearch.co.uk/lab/hstssupercookies
 - [HSTS [sniffly]](http://zyan.scripts.mit.edu/sniffly/) - **h**ttp://zyan.scripts.mit.edu/sniffly/
 - [HTML5](https://www.youtube.com/html5) - **h**ttps://www.youtube.com/html5