Recently, I had an problem with Joomla! 1.5 where they would log in to the administration panel with IE 7 and their browser began requesting index.php?option=com_admin&tmpl=component&task=keepalive thousands and thousands of times. It was like 5-30 requests per second for this page. Though that's a lot, it wouldn't put TOO much strain on the server since the page being requested didn't have any content on it whatsoever.
The real problem was that the end user was walking away from his machine so it was pretty much flooding the server with useless traffic. Another implication of this is that since the ever-naughty behavior.keepalive function was doing its job (a little too well, of course), the website administrator may be out of the building but his session is still alive and well for any passers-by to take advantage of.
Though the flooding wasn't happening in Firefox or Opera, I decided to edit it out of the code: JHTML::_('behavior.keepalive');
A quick search and replace on the joomla install commented it all out and the problem went away.
If you happen to experience this problem and you're using 1.5 RC3 the function can be found in:
[Joomla! Root]/administrator/components/com_content/admin.content.html.php line 554
[Joomla! Root]/administrator/components/com_media/views/media/view.html.php line 86
[Joomla! Root]/components/com_content/views/article/tmpl/form.php line 212
[Joomla! Root]/plugins/system/legacy/classes.php line 1275
[Joomla! Root]/templates/beez/html/com_content/article/form.php line 190 but this doesn't matter if you aren't using this template, of course.
