Distrust
I generally don't think that trust is something that can be measured or secured through some device, agreement, or any kind of remote or face-to-face interaction. My feeling is you could have as many reasons to not to trust someone you meet up close as someone you meet online. I mean, if they really want to deceive or betray you, they could do it even if they were very close to you.
of course, if it is someone you have never met in person, this would be a different matter. Seeing what they look like would give you a better sense of what they are like, and if the basics of who they claim to be are true. It's possible that meeting someone online you wouldn't be sure if they are lying to you about who they are, but hopefully having a more complete image of them will help ease your worries.
That said, I am interested in the thin line between distrust and paranoia. Most of the times it only takes common sense to know whether or not you should trust someone. If you are talking to people you know nothing about, you could build trust slowly, or by getting external information about them. If you are afraid that they are not revealing something, then you could try looking when they do not think they are being observed. An idea would be a platform that connects people to each other only if they are willing to be connected to the other person whenever that person wishes, with no step in which the person "agrees" to accept the connection, then you would hopefully be a little more convinced that the other person doesn't have something to hide. But that sounds an awful lot like surveillance/spying.
On the flip side of distrust is, obviously, trust, or faith in something. An interesting commentary on the untrustworthiness of the internet as a medium to meet and interact with people would be to use the internet as a source of "trust" so as you are talking to someone, you will get a background check with any online traces of the other person, or who they claim to be. Sure that could just lead to even less trust, but it is faithful to the technology -- you have to trust something. It is also somewhat taboo, to openly admit that you are not trusting someone, and are "stalking" them to see if they are telling the truth. if the other person trusted you and found out that you were being so paranoid, would they still trust you?