Late last night I noticed that the link data for my sites was missing in Google Webmaster Tools. I assumed this was the result of some routine maintenance on Google's end and thought nothing of it. Apparantly this may not be the case, as I came in to work this morning and discovered the the link data was still missing, and was also missing for every single one of our client's sites (both external links and internal links).
I'm not going to throw out wild theories about what Google is up to, but it will certainly be interesting to see if anything comes of this latest development. If I had to hazard a guess, I would say the most likely explanation is an update of the link database. However, when it comes to Google, as we all know, the only people that really know what's happening are the people at Google.