@capobecchino sempre a proposito del rel="me" e della ricerca sociale di google, ecco la best practice:

How does nofollow work with the Social Graph API (rel="nofollow me")?

If you host user profiles and allow users to link to other profiles on the web, we encourage you to mark those links with the rel="me" microformat so that they can be made available through the Social Graph API. For example:

<a href="http://blog.example.com" rel="me">My blog</a>

However, because these links are user-generated and may sometimes point to untrusted pages, we recommend that these links be marked with nofollow. For example:

<a href="http://blog.example.com" rel="me nofollow">My blog</a>

With rel="me nofollow", Google will continue to treat the rel="nofollow" as expected for search purposes, such as not transferring PageRank. However, for the Social Graph API, we will count the rel="me" link even when included with a nofollow.

If you are able to verify ownership of a link using an identity technology such as OpenID or OAuth, however, you may choose to remove the nofollow link.

To prevent crawling of a rel="me nofollow" URL, you can use robots.txt. Standard robots.txt exclusion rules are respected by both Googlebot and the Social Graph API.