Hello there, just noticed the site: operator results on Google are different for my entire network of websites (a couple hundred thousand results difference) . Fearing a penalty I checked my traffic and it was normal, I then started checking other competing websites, and it's all the same. One of my sites previously had 12k indexed pages now it's on 120k but with the site:/* operator only a massive 34 results are still there. The other one used to have 80k results now it has about 3000 and with the site:/* operator it's down from 28k to 320. Check your sites people - something's cocking at Google.
Yes I noticed this similar the other day. I think maybe it has to do with duplicate content. Is any of your sites pages autoblogged or duplicate content? How do you have hundreds of thousands of pages? Is it a forum?