The DON'T & DOs of SEO
Don't use blackhat seo technique, this SEO technique is very risky thing to do, and it's also very unethical.
One of the most severe consequences of using black hat seo is that your website would likely get penalised by search engines like Google.
This black hat seo can be in different form, one of the most popular black hat seo techniques is to use hidden texts containing all the keywords.
The bottom line is, black hat seo is not worth doing it at all, and shouldn't be used.