Come on. This is a tool that has a legitimate purpose - if you buy advertising on FB, you use pixel trackers to find out if it was effective. Did the ad you showed the user lead to them doing the thing you want - buying a shirt, signing up for a newsletter, or in this case, making an appointment? They shouldn't be optimizing on medical search terms, but this is a problem with usage, not the tool.
I disagree. Exposing your users (including non-FB users who visit your website directly) to FB stalking isn’t a good enough justification (and in breach of the GDPR).
You can track advertising effectiveness yourself by having all your ads point to a unique URL with some query parameter (“campaign_id=123”) which preserves the privacy of everyone. FB can stalk their users on their own properties but at least non-FB users are protected from it.
