Use jQuery for Bootstrap 3 new radio buttons btn-group.

Twitter Bootstrap Radio Button Form Inputs.html

<form>
<div class="btn-group" data-toggle-name="is_private" data-toggle="buttons" >
        <label class="btn btn-default">
          <input type="radio" name="private" value="1"> Yes
        </label>
        <label class="btn btn-default">
          <input type="radio" name="private" value="0"> No
        </label>>
</div>
<input type="hidden" name="is_private" value="0" />
</form>

Twitter Bootstrap Radio Button Form Inputs.js

$(function() {
    $('div.btn-group[data-toggle-name]').each(function() {
        var group = $(this);
        var form = group.parents('form').eq(0);
        var name = group.attr('data-toggle-name');
        var hidden = $('input[name="' + name + '"]', form);
        $('label', group).each(function() {
            var button = $(this).find('input[type="radio"]');
            $(this).on('click', function() {
                hidden.val($(this).val());
            });
            if (button.val() == hidden.val()) {
                $(this).addClass('active');
            }
        });
    });
});

does the label have a value ? I think line 10 should be hidden.val(button.val());