> What's your source?
The ICO. I've called them up, and they've confirmed their 2011 interpretation of personal data:
https://ico.org.uk/media/for-organisations/documents/1591/pe...
An IP address is "personal data" in the same way that "lifestyle information" or a "location" is. That someone can combine an IP address with other information to personally identify someone is important, but it doesn't prevent me from logging personal data.
https://ico.org.uk/media/for-organisations/data-protection-r... (20th Oct 2017):
> Like the DPA, the GDPR applies to ‘personal data’. However, the GDPR’s definition is more detailed and makes it clear that information such as an online identifier – eg an IP address – can be personal data