Hello Bettina,

There's 2 ways to do this.

1. As Dennis pointed out above, turn on lock down mode. Lockdown mode will enforce non logged in users to login / create account before being able to see anything on the site.

2. If you simply only want to turn off the stream on the dashboard, then edit the theme file /components/com_easysocial/themes/wireframe/dashboard/default.guests.php and remove the block of codes below:

P/S: You might also want to create a template override if you are going with #2. You can find the documentation for creating template overrides at http://stackideas.com/docs/easysocial/administrators/templating/template-overrides