In a court case vs Planet 49 the EU has ruled that you can’t start collecting data just by showing a warning that you are doing so or by having a preselected tickbox stating it’s OK to collect data. The user has to actually go and click the tickbox or OK before any data collection is allowed.
the consent referred to in those provisions is not validly constituted if, in the form of cookies, the storage of information or access to information already stored in a website user’s terminal equipment is permitted by way of a pre-checked checkbox which the user must deselect to refuse his or her consent.
Source: CURIA – Documents
This is a good thing which fights off dark patterning – forcing users into things they don’t consent to or understand, of which there is more than enough of thank you very much.