Add metrics and update privacy info

1 files changed, 12 insertions, 1 deletions

diff --git a/privacy/index.md b/privacy/index.md
index 227e797..195e52f 100644
--- a/privacy/index.md
+++ b/privacy/index.md
@@ -10,4 +10,15 @@ This site contains scripts loaded from github.com in order to display code snipp
 
 This site uses the CloudFlare CDN. Limited analytic data are kept by CloudFlare. CloudFlare also sets a `__cfduid` cookie for overriding IP-based security restrictions. You can read more about this cookie [here](https://support.cloudflare.com/hc/en-us/articles/200170156-What-does-the-CloudFlare-cfduid-cookie-do-). You can also read [CloudFlare's privacy policy](https://www.cloudflare.com/security-policy).
 
-If you have questions or concerns, please [shoot me a note](mailto:hi@benburwell.com).
+Furthermore, very limited metrics are collected and recorded for my own use. A [custom tracking script](https://github.com/benburwell/benburwell.github.io/assets/scripts/metrics.coffee) is used and metrics are stored in an isolated app running on Heroku. The data collected from all visitors are limited to that which cannot be used to identify the visitor, and includes:
+
+* page load timing information (using the [Navigation Timing API](http://www.w3.org/TR/navigation-timing/));
+* the path and title of the page visited.
+
+The metrics script respects the visitor's [Do Not Track](https://en.wikipedia.org/wiki/Do_Not_Track) preference. If the Do Not Track flag is _not_ set, the following information is collected in addition to the information collected about all visits:
+
+* language;
+* browser (not the entire User-Agent string);
+* referring domain.
+
+If you have questions or concerns, please [shoot me a note](mailto:ben@benburwell.com).