I have a Piwik installation tracking about 10 websites. I use the iframe for opt-out with the CustomOptOut plugin to style the iframe for the different sites. But I have to switch tracking for the sites separately. Turning tracking off on one site shall not turn it off on another site tracked by the same Piwik instance. The idSite parameter has no impact on this issue, it’s just used for styling. Is it possible to do so?