I'm sorry we let this happen. Users had reported Claude would hallucinate names for things like @author tags, since it didn't have context on the account. So we added the account email in the model's context for signed-in users. But when Claude wrote a command itself, like a curl call, it sometimes put your email address in the User-Agent as a contact address. Some sites ask agents for a contact, and Claude would sometimes provide the email address in its context.
Until the next release arrives, 2.1.317 and later have a built-in mod (on by default) that asks you before Claude runs a web tool call or a curl-style command containing your email (mpoteat covered it here: https://news.ycombinator.com/item?id=50386031). But it still doesn't prevent all cases, like when Claude writes a script and runs on its own. The stable channel is still on 2.1.311, so update to 2.1.317 or later.
Again, this should not have happened, and we should've caught this behavior earlier.