When writing your counter-notification you need to state that you will accept lawsuit from the parties sending the take down notice. Doing so will absolve your ISP of all blame and prevent their taking further action against your website. You must further specify your reason for sending a counter notification. This could be because the material is not copyrighted, the complainant does not hold the copyright, the copyright has expired, or because your use of the material in question is legally protected in some other way. Separately, even if the material is in violation, if the complaining party has not followed proper protocol in sending their take down notice you are perfectly within your rights to send a counter notification, providing you specify this clearly as the reason for such a reply. If no legal action is taken within ten days any modifications, or removals, made by your web host should be restored. In any event, it is unlikely that the complainant will take it any further seeing as they would have to take legal steps in a court in your jurisdiction likely to be a costly process for them and not usually worth it, taking into consideration the relevant travel and legal expenses (unless youre dealing with some major company). Be warned, however, that if they do decide to pursue it, and win, you may be liable for their legal expenses as well.