Depending on the browser plugin, they can be there to prevent snooping. Going to booking.com (chosen by percentile dice from list of top 100 websites), there w

Depending on the browser plugin, they can be there to prevent snooping. Going to booking.com (chosen by percentile dice from list of top 100 websites), there were several snooping javascript downloads blocked by ublock origin, from google analytics, google ad services, and lms-analytics.