"Party line" implies that it's a position everyone's obliged to take as part of being a party member, rather than something freely and independently reached.

And I suspect the main driver for GDPR cheering is that nothing else has been done about so many other privacy incidents. We can look back on HN and find such things as the massive Equifax leak (the next one of those is going to be interesting!) and the smart TVs that exfiltrate a list of all files on any media inserted.