It not about user security. You can encrypt your data with gpg and send it via pastebin, zerobin, or mailinator to your accomplice and secure. ZeroBin is about

It not about user security. You can encrypt your data with gpg and send it via pastebin, zerobin, or mailinator to your accomplice and secure. ZeroBin is about lifting the liability off the service provider. Think the tired old "does linking constitute a copyright violation?" question. If someone posts a list of magnet links or torrent URLs to ZeroBin, they can claim plausible deniability: they cannot know the content of the pastes they host. This reduces to deep questions about internet freedom. For example, if ZeroBin couldn't for some legal reason host "infringing" links, they couldn't host any links, and Tor, I2P, Freenet, and other onion/mix networks would be similarly illegal. Or can it be illegal to participate in an anonymous networks or not? Some parties would like to see the answer to be "yes". But we all know that there's copying bits and there's copying bits: at some point it doesn't matter, at some points bits can't be legal or illegal but just bits. Technology like ZeroBin can help drive the liability question down to the very, very basics where it can be eventually solved.