The Internet is a messy place. There are loads of hackers, spammers, and other cybercriminals out there. This is why Google penalizes many sites. Unfortunately, many people are complaining that Google is penalizing their website without any explanation or warning. This may seem like a careless mistake but Google always has your best interest at heart.
In this video, one of the Google Webmasters explains this issue. It seems that Google is not giving warnings or explanations to anyone; however, this is not true. Google sends out warnings and explanations to many users but not to all. The problem is that a large percentage of users who get their website penalized are indeed cybercriminals such as hackers, spammers, and the like. If Google were to give explanations or warnings to these users, they could easily use that information to continue their work on another site or perhaps find some way around it.
Unfortunately, Google cannot always determine which users are criminals and which are simply making mistakes or becoming victims. This is why it is unfortunate that some users are penalized without warning or explanation. It should be noted that the people at Google are simply doing their jobs and doing their best to keep users safe.
Why aren’t penalized sites notified in Webmaster Tools? –