[dazc]

Breaking News: Google de-indexes random sites all of the time and there is often no obvious reason why. They also penalize sites in a way where pages are indexed but so deep-down that no one will ever find them. Again, there is often no obvious reason.

[p410n3]

Do you have any resources here? The /r/seo subreddit seems vers superficial coming from an web agency background so its hard to find legit cases versus obvious oversights. Often people make a post describing a legit sounding issue on there just to let it shine through that they are essentially doing seo spam.

[dazc]

It's something you'll experience if you publish many sites over time. Can't point to any definitive sources, many of the reputable search related blogs are now just Google shills.

[hackerbeat]

Totally. They've completely lost the plot.