As a European who had to make sure the provisions contained in this law were implemented on a few high-traffic sites targeting consumers, I can definitively say that the law is at least a little bit "controversial" and unclear. We had to request the assistance of a law firm to make sure we complied.

Originally it looked like you had to give the users an option to decide if they allow the use of tracking cookies or not, potentially having to deal with NOT pushing such cookies in case the user did not consent. In reality, most of the implementations I've seen are just informing the customers that tracking cookies are used and let them know that usage of the site represents consent of such usage, adding that they can modify the browser preferences if they want to modify their cookie preferences. Additionally, you have to link to a cookie policy that you publish on the site.

As a clarification, this law does not apply to cookies in general: certain cookies, sometime referred as technical cookies (e.g. session) are exempted as long as they're not used for tracking purposes.