Just about everything in civilization works on the honor system.
No armed guards at the local grocery store, no pat down as you leave the library. Most people cross the street without fear of crazed hit and run assassins.
Great marketers are able to deliver customer service because they're willing to give people the benefit of the doubt. They tend to take your word for it.
Of course there are bad actors. One out of a thousand people will cheat on that test or rip off that store. When LL Bean or Patagonia offers a no-questions-asked money-back guarantee, some jerks decide to buy an outfit, go on a trip and then return it all.
If you spend all your time worrying about these folks, you end up underserving the other 99% of the population. Take the write off. That's what successful marketers do.
When we move online, though, two things happen. First, word among the black hats spreads fast. One person starts ripping you off and suddenly it's a hundred.
Worse, the ripoffs and bad actions can scale. Sure, only one in a thousand email users is a spammer. But one spammer, aided by a computer, can send a million or more emails in a day. Suddenly, the people who violate the honor system are able to drown out the good guys.
Just like the real world, though, if you spend all your time preparing for and defending against the black hats, you'll never accomplish anything. If you assume that every single interaction online is fraudulent until proven otherwise, people will just move on to the competition.
So, online, you're between a rock and a hard place. The first opportunity is to treat your friends better than ever, because word of mouth online is incredibly powerful. The Net brings significant leverage--you can spread ideas farther and faster.
The temptation is to embrace only the advantages of the web and insist on eternal vigilance against the possiblity of getting ripped off. To act as if everyone online is a criminal. To assume that the moment you are generous or trusting, squadrons of bad actors will exploit your generosity. I don't think that's the answer. If you treat people like criminals, the good ones will leave, because people have a choice.
There's a different path. Awareness of the potential problem helps you keep your eyes open. You can watch the trends, be aware, but still embrace the honor system. Realize that the vast majority of your customers will always want to do the right thing. Look both ways before crossing the street... but still cross.