Lithium PHP framework CSV media handler - blacklists data not intended for export. See StackOverflow question "How do you remove specific fields from all entities of a record set in Lithium?": http://stackoverflow.com/questions/17189664/how-do-you-remove-specific-fields-from-all-entities-of-a-record-set-in-lithium/17202455

DownloadsController.php

<?php

namespace app\controllers;
use app\models\Downloads;

class DownloadsController extends \lithium\action\Controller {

    public function index() {

        $this->request->privateKeys = array('id', 'user_id');

        // Dynamic conditions
        $conditions = array(...);

        $downloads = Downloads::find('all', array(
            'fields' => array('user_id', 'Surveys.name'),
            'conditions' => $conditions,
            'with' => 'Surveys',
            'order' => array('created' => 'desc')
        ));

        return compact('downloads');
    }

}
?>

media.php

// config/bootstrap/media.php
Media::type('csv', 'application/csv', array(
    'encode' => function($data, $handler, $response) {
        $request = $handler['request'];
        $privateKeys = null;
        if ($request->privateKeys) {
            $privateKeys = array_fill_keys($request->privateKeys, true);
        }
        // assuming your csv data is the first key in
        // the template data and the first row keys names
        // can be used as headers
        $data = current($data);
        $row = (array) current($data);
        if ($privateKeys) {
            $row = array_diff_key($row, $privateKeys);
        }
        $headers = array_keys($row);
        ob_start();
        $out = fopen('php://output', 'w');
        fputcsv($out, $headers);
        foreach ($data as $record) {
            if (!is_array($record)) {
                $record = (array) $record;
            }
            if ($privateKeys) {
                $record = array_diff_key($record, $privateKeys);
            }
            fputcsv($out, $record);
        }
        fclose($out);
        return ob_get_clean();
    }
));