For the people asking whether email tracking pixels are subject to GDPR and similar EU/UK privacy laws, the answer seems to be YES.
The UK Information Commissioner's Office (ICO) just published updated guidance on cookies and pixels here: https://ico.org.uk/media/for-organisations/guide-to-pecr/guidance-on-the-use-of-cookies-and-similar-technologies-1-0.pdf
It was for exactly this reason that we stripped personally identifiable tracking functionality and historical data from our CRM: https://faelix.net/news/201805/tracking-emails/
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