Is it really necessary to disavow links from spammy social bookmarking sites?

[Aathvika]

Yes definitely you should disavow spammy links pointing your website. Because it will affect your websites overall performance.

[bavya]

If you find your link is affecting the ranking of a website then you can disavow them.

[darchie9717]

yes, it is necessary to disavow links from spammy social bookmarking sites. Google just rolled out Penguin 4.0 on 23rd September 28, 2016, which will impact search results in real-time and at page levels. Penguin 4.0 Google update is based on page-level backlinks rather than the entire site as it used to be in the previous updates. For e.g. if an inner section or a particular page is linked from a relevant high-quality webpage, it will rank on the SERPs no matter the home page is ranked or not. It is vice versa for a link from a Spammy or manipulated page.

[Aathvika]

Yes you must disallow spam and irrelevant backlinks in order keep your website safe. Otherwise there is more choice for your website to get penalized and there will be a drop in your keyword rankings.