Seems the "lets enhance the mechanisms explicitly built-into browsers/web-platforms for collecting information about how user's interact with webpages, apps, etc" folks have been busy. I figured a thread was in order, to mention some recent developments and exchange info. Hyperlink-Auditing aka <a ping> has been around for awhile. It is a pure phone home mechanism meant to inform one or more [cross-domain] servers of which links you click on (and when). Chrome/Chromium Already built into releases Enabled by default: ? Browser settings to control it: ? To disable: ? Firefox Already built into releases Disabled by default in 30.0, etc but people are (once again) pushing to have it enabled by default. Furthermore, some are trying to remove the preferences which control it. Browser settings to control it, which hopefully will remain: browser.send_pings (bool) browser.send_pings.max_per_link (number) browser.send_pings.require_same_host (bool) To disable: set browser.send_pings = false via about:config, user.js, or autoconfig. Some extensions should also block it. Beacon aka navigator.sendBeacon() is newer, and has recently been checked into at least Chrome/Chromium and Firefox. It is a pure phone home mechanism meant to send <whatever> data to (potentially cross-domain) servers, particularly when leaving a page. Chrome/Chromium Already Implemented Which builds, enabled status, etc I don't follow so: ? Browser settings to control it: ? To disable: ? Firefox Already Implemented In FF 30.0 (disabled by default), plans are to enable it soon Browser settings to control it: beacon.enabled (bool) To disable: set beacon.enabled = false via about:config, user.js, or autoconfig. Some extensions should also block it. Note: I spent a modest amount of time trying to understand the Firefox situation. At present, it appears that a Beacon hits shouldLoad() as an entirely new aContentType (TYPE_BEACON). Furthermore, it seems the Mozilla guys are only preflighting *some* cross-domain beacons. So conceivably, there might be some filtering extensions that won't block beacons properly. I tried Firefox Portable 31.0a2 with the latest ABP development build, and that seemed to work OK. Which I think is due to ABP treating non-recognized types as OTHER and applying its rules to OTHER. Long story short, I think this newer "feature" may call for some attention/testing to make sure extensions block it when expected. I can't afford the time to look into the Chrome/Chromium situation, to answer those ?s up above, and try to determine if its implementation might pose any problems for filtering extensions. Perhaps someone else will have the time to do so. I don't know of any public tests pages for these "features", but for those who have a [local] server and would know how to go about things, attached are two test pages I used to do some testing on Firefox.