We could detect the username of users logged in wordpress, joomla, drupal, popular CMS here. By reading cookie matching a name and looking in the value, we can see the username and set as custom variable automatically.
This would be useful!
would be also very interesting for magento e.g. small shops with only some but often returning vistors/customers...
Several things: 1. Automatically setting the username as a custom variable could potentially create privacy issues. 2. What if users already set n other custom variables? 3. Should this not be a feature provided by the Piwik integrations for popular CMS here? E.g. could this not be done by WP-Piwik for Wordpress?
1) it woudl be disabled by default
2) It would be only set if there is an empty slot (as scope=visit)
3) it's easier to implement it once in the piwik.js rather than have 10 plugins each implement the cookie reading + custom var setting (so, IMO it's more realistic / easier to do it in core).
maybe it could be done together with #3490