Selectively hide events from specific user roles

// Snippet now hosted here: https://gist.github.com/elimn/6a57feaec4bd09db9923

add_filter('pre_get_posts', 'event_cat_permissions');

function event_cat_permissions ($wp_query) {

        // Include all posts on admin views
        if ( is_admin() ) return $wp_query;


        $exclude_cats = array();

        // Exclude cats if not admin... copy/modify this logic for each custom role
        if (!current_user_can('administrator')) {
                $exclude_cats[] = 'exclude-slug';
        }


        // Join with current tax query if set
        if (is_array($wp_query->tax_query))
                $tax_query = $wp_query->tax_query;
        else
                $tax_query = array();


        // Setup an exclude from the tribe_events_cat taxonomy
        $tax_query[] = array(
                'taxonomy'  => 'tribe_events_cat',
                'field'     => 'slug',
                'terms'     => $exclude_cats,
                'operator'  => 'NOT IN'
        );

        $wp_query->set('tax_query', $tax_query);

        return $wp_query;
}