Activity Portlet shows activity for private content
To reproduce this issue:
1. login as admin/admin and create a private site "site a" and add a blog entry "blog in private site"
2. create a user "test user" and view admin's profile page, "test user" will be able to see that admin wrote a blog entry. this should not be the case.
3. in the globak search, search for "blog", you will also see the blog in the search results. this also should not be the case.