I lost faith in PIA caring about privacy of its customers when I noticed how they use unique tracking codes in their newsletter emails. I never received a response when I asked about it.
Not apologizing for PIA - They definitely shouldn't be doing it if they're trying to advocate for privacy. But just stating it's extremely common practice and the default for most email services. I use it on my e-commerce websites so that I can send specific emails to people who have viewed a certain page, abandoned checkouts, opened a certain email but didn't convert, etc.