First of all, it's not just one page, it's MANY websites and every index.php, default.php, home.php, login.php or .html or .htm has been altered. And the defacement happened not just in the main directories of websites, but also in nearly every subdirectory as well. So, it's many, many websites and pages.
The alert system that I had in mind may not necessarily send a notice to website owner automatically by the system, but would be sent by LP admin. I am assuming that LP knew that there was an issue with websites being defaced, just because of the sheer number of affected accounts. But, no e-mail was sent to anyone informing them of a problem (at least not to me, and I host a lot of sites.)