GDPR allows individuals to request erasure verbally or in writing, and the data controller than has one month to respond.
However all organisations must be able to handle GDPR requests via any communication channel. Eg. They need to treat a data deletion request sent via twitter DM as a valid request if they have an official Twitter presence.
It is insufficient to require the customer fill out a special web form.
> The GDPR applies to: [...] > 2. a company established outside the EU and is offering goods/services (paid or for free) or is monitoring the behaviour of individuals in the EU.
Assuming account names or the content of comments constitute personal data within GDPR, I think YCombinator falls into this group.
Edit: I forgot HN collects an optional email address too, which is definitely personal data.
Details here: https://www.ycombinator.com/legal/#:~:text=Hacker%20News%20I...