Anonymous users can search the version comments in a document or in a picture in SharePoint Server 2007

You include information in the Version Comments box when you upload a document or a picture to a Microsoft Office SharePoint Server 2007 document library. When you do this, anonymous users who visit the site can search for the document or the picture by using words that were included in the Version Comments box.

By default, anonymous users can view the check-in comments and the version comments that are included in a document or in a picture in SharePoint Server 2007.

To work around this behavior, you can turn off indexing for the check-in comments and for the version comments. To do this, follow these steps:

1. Click Start, point to Administrative Tools, and then click SharePoint 3.0 Administration.
2. On the Central Administration page, click Shared Services Administration.
3. On the Manage this Farm's Shared Services page, click the default shared services provider.
4. On the Shared Services Administration page, click Search Settings under Search.
5. On the Configure Search Settings page, click Metadata Property Mappings.
6. On the Metadata Property Mappings page, click Crawled Properties.
7. Under Crawled Properties View, click SharePoint.
8. Under Crawled Properties View - SharePoint, click ows__CheckinComment(Text).
9. On the Edit Crawled Property page, click to clear the Include values for this property in the search index check box, and then click OK.
10. Repeat steps 8 to 9 for the ows__ModerationComments(Text) property.

This behavior is by design.