During the last weeks several people blogged about open phpinfo() pages (here and here). They usually contain a lot of information about the server and therefore should not be open to the public and especially not to search engines like Google that will keep them for a long time in their archive.
Because of this the Suhosin extension does now add an extra META TAG to the HTML output of phpinfo() that forbids indexing and archiving by robots. For fairness reasons following the embedded links is still allowed to robots, because a lot of projects like dotdeb and suhosin add links within phpinfo() to their project site to get atleast a few backlinks for their work, that might result in a better search engine positioning.
Future versions of PHP will come with a similiar META TAG by default that also forbids following the backlinks. Suhosin will correct this on the fly. Ironically those in favor of disallowing backlinks from within phpinfo(), are those developing PHP applications that contain similiar backlinks on every page.