Privacy Policy: Add legitimate interests statement on web logs

This adds a legitimate interests statement on our collection of personal
data in web server logs.

hub/templates/hub/privacy.html

@@ -37,10 +37,14 @@ <h2 id="legal-basis">Legal basis for processing</h2>
 
             <p>If you are an MP, and your information has been used on the site, this is being stored under the legal basis of GDPR 6(1)(f) Legitimate interests. In our assessment, this is already public information about MPs, with a minimal privacy impact, being used in a way that MPs should reasonably expect, to provide a public benefit – transparency on what MPs do as part of their public role.</p>
 
+            <p>When you interact with this site, information about the visit stored in our web server logs is stored under the basis of GDPR 6(1)(f) Legitimate interests. We collect this in order to analyse usage of the site, facilitate debugging and prevent abuse.</p>
+
             <h2 id="retention">How long we keep your data</h2>
 
             <p>In all cases listed above, we retain your personal data until such a time as it is removed from our upstream data sources (listed here) or you ask us to remove your details.</p>
 
+            <p> As stated above, we retain information logged in our web server logs for 28 days.</p>
+
             <h2 id="sharing">Who we share your data with</h2>
 
             <p>If you have a personal account on the site, the personal details associated with your account (see above) are accessible only to three charities that run the site – The Climate Coalition, mySociety, and Green Alliance – and will only be used for the specific purpose of running the Local Intelligence Hub. We don’t share this personal data with any other charity, public body, or commercial organisation, unless you give us permission to do so, or we have to do so for legal or compliance reasons.</p>