Every now and then, a 'viner goes off the deep end. Often, they'll expose other 'viners personal email addresses by forwarding emails they've received to other people. And sometimes, a 'viner may inadvertently share an email someone else sent them - it's not always with malicious intent.
Many 'viners never send emails to other 'viners, and don't respond when they get emails. But if you do, the solution is simple. Set up an email account that's dedicated to Newsvine, using your screen name or something rather than your real name. Then, if someone you had previously emailed decides to start being an asshole, you have nothing to worry about.
Practice safe cyber here just as you would anywhere else on the Internet. Use a cyber condom.