Google does site: searches for my site

[NedProf]

In the past weeks I see some strange searches from Google California. All searches are from 3 different IP's:

66.249.85.85
72.14.195.224
74.125.16.65

And the strangest thing is the searches they do:
site:example.com title-of-article-one
site:example.com another-article-i-wrote
site:example.com and-the-last-article

The urls of my site look like this:

http://example.com/index.php/title-of-article-one/

What could this be? What are they doing?

[tedster]

My best guess would be some kind of testing related to this news:

New Search Box Under Sitelinks [webmasterworld.com]

Those new search boxes use the site: operator. They may be testing your domain to see if it should be awarded the site search box.

[g1smd]

Is it a test for Duplicate Content in page titles?

[ecmedia]

We are all having similar problems in which Google is searching and indexing pages that we never created. It is being discussed here
[webmasterworld.com...]

[tedster]

I also thought there might be a connection to that thread and another as well, ecmedia - and the two phenomenon might be part of the same "project". However there are some critical differences:

1. In this case the IPs are NOT googlebot - they are a user from a different IP at Google.

2. A spider requests a URL, but these look like referers from a Google SERP after a sirte: operator search.