What Tampermonkey's terms say
Tampermonkey's terms of service and privacy policy have 8 rated points: 0 serious, 3 bad, 0 worth knowing and 5 good. 8 apply whenever you use the site, signed in or not; 0 only once you have an account.
Whenever you use Tampermonkey
Bad 3
Third-party cookies are used for advertising
Where it says this ↗You are tracked via web beacons, tracking pixels, browser fingerprinting, and/or device fingerprinting
Where it says this ↗Third-party cookies are used for statistics
Where it says this ↗
Good 5
Your personal data will not be used for an automated decision-making
Where it says this ↗This service claims that your personal data is not being sold
Your personal data is not sold
Where it says this ↗Do Not Track (DNT) headers are respected
Your browser's Do Not Track (DNT) headers are respected
When viewing the site's privacy policy (www.tampermonkey.net/privacy.php), the section titled "13. Data protection provisions about the application and use of Matomo" says "You are not being tracked since your browser is reporting that you do not want to. This is a setting of your browser so you won't be able to opt-in until you disable the 'Do Not Track' feature." Screenshot: ibb.co/ZYjNjKb
Where it says this ↗The service claims to be GDPR compliant for European users
Where it says this ↗The data retention period is kept to the minimum necessary for fulfilling its purposes
Where it says this ↗
If you have a Tampermonkey account
No account-only points rated.
The documents
Ratings by ToS;DR volunteers; they can lag behind the current terms. Not legal advice.