On Monday we reported that Google spanked the adult porn industry by penalizing many of the sites. There were many theories as to why those sites were penalized. It wasn’t all the adult sites that were penalized but a nice percentage were.

Sometime last night, Google seemed to have reversed the penalty. An updated Google Webmaster Help thread reports two of the adult webmasters saying their sites are back to normal in the Google index. One said:

What exactly caused the temporary penalty is not yet known. It might have been a misclassification of something all those sites are using. Hard to know exactly without a Googler coming in and letting us know.

One adult webmaster wants to know why this happened. Why did he lose his rankings and revenue for several days due to this Google glitch? He asked:

I am not sure if all these adult sites have been restored in Google yet or if it was just a handful, but it seems like many are coming back.

Forum discussion at Google Webmaster Help.