Go to Google and type in your email address.
If you don't like where it's listed, report it to Google and the web site owner to try to get it removed.
Many news groups publish people's names and email addresses on web sites - and not only that they publish these news groups get copied to all kinds of third party sites - so your name and email address is spread all over search engine results.
This makes it extremely easy for hackers and spammers who scan web pages to pick up your email address all over the place.
One site changed all the email addresses to something like this name <at> emailaddress.com
That doesn't really hide the address.
Try to contact these web sites and ask them to remove your name and email address. Some of them will do it. After many contacts some web sites still have not responded and other web sites have said they will remove the pages but it takes forever for them to remove it and even longer for it to be removed from search engine caches so it doesn't show up in search engine listings.
Should it be legal to post someone's private contact information without consent?