There's a massive difference between suing and striking. Suing someone means you're intending to take them to court. A copyright strike is different. I forget if copyright strike implies DMCA or content ID. DMCA possibly involves lawyers (honestly can't remember) but it removes the content from the site and that's it (you only go to court if you disagree and they push back). Content ID is an automated process that either removes sounds, portions of videos, or takes a portion of ad revenue.