Most site owners use the webmaster console to check the progress their site is doing on Google. To further help site owners Google started sending messages to site owners about the unnatural links that point towards the site. Let me give you some more information about these messages.
Google has been sending out link messages for many months now. There are different ways in which Google responds to unnatural links pointing to sites. Where Google is convinced that there is link spamming happening due to a large number of unnatural links being pointed they just reduce their trust in the site. In case this has happened to your site then it is advisable to remove as many links as possible and then send a reconsideration request to Google for your site. A few sites do charge you to put links up and then take them down, in such a case you need to inform Google about that in your reconsideration request. Such sites are then dealt with by Google.
In less severe cases Google just distrust links it believes are spammy in nature. This does not affect the overall ranking of the site. This is targeted action taken by Google shows that they are on top of things. However such messages are a warning sign for you.
In some cases Google is convinced that certain links are unnatural and Google then makes sure that you do not get search rankings for such specific phrases. Google also discourages you from putting keyword rich anchoredtext in your widgets. When such a message is received it means that your widget is not working and is preventing your page from getting ranking for the particular phrase.
Google also does not take paid links lightly. If paid links or posts appear on your site it is advisable to take them down immediately so that your page ranking is not affected. However, Google does ignore links where the site has itself not violated the guidelines.
Recently Google enabled the ability to download backlinks to your website by date. Whenever you get this message it is advisable that you check the most recent links to your website to see if something unusual is happening. It could be that someone in your company is doing a widgetbait or paid links or linkspam. In any case you need to clean this up.
The messages you receive from Google reflect the severity of the problem. And you have to stay alert all the time to ensure your site and page rankings don’t get affected.