I'm not really sure where you're going with this. If you're advising people to be careful about meeting online friends then I agree wholeheartedly. The internet can be loads of fun and a great source of education but its also a place where people of a certain disposition can safely lurk behind a pseudonym and get away with the kind of language, behavior and even depravity that in public you ought to get flogged for.
But that's not to say there aren't regular people online too, of course there are, really it depends where you go online to talk/meet. Go somewhere dodgy and you'll no doubt meet dodgy people. I think there are plenty of people in TZ who have met up in R/L or who are planning too (and some who have and who have found romance which is wonderful) but the point is not to rush into it and get to really know your friend - as you say, build up a trusting relationship with them first, don't just chat to someone for an hour and then rush off to meet therm knowing next to nothing about them.
If you're complaining over the fact that your parents are a little suspicious about you meeting this person then that's a different kettle of fish. It also depends on how old you are, how old the friend is, where you met them online, what kind of relationship (ie do you think of them as your girlfriend) and where you want to meet in R/L. As a parent myself I'd want to know all the details before I let my kids meet someone they met online. I know that for a lot of youngsters this seemingly 'over-protective' attitude we moms n dads take really seems to suck, we're spoiling your fun, cramping your style, messing with your affairs etc but do try look at it from our POV just for a moment. Until I had kids myself I couldn't see why my mom acted like she was trying to spoil my fun all the time when all she was doing was worrying herself sick about what might happen to my trusting and oft-naive little head, and if the internet had been available then I know we'd have had even more arguments. Internet friendship scare stories in the media are rampant and often this is enough to put some parents mind on edge and give you an outright 'no' to meeting anyone. Personally I would possibly agree to a phone call or two from them (and maybe speaking to their parents myself) then if the friendship seemed firm, maybe a chaperoned meeting, keeping an unobtrusive background presence but also there to ensure it really is a 15 y/o boy and not some 53 y/o guy with a beerbelly. At the end of the day its down to the individual I guess.
Of course of you're an adult then you're responsible for your own actions, I've met several online friends in real life and got on like a house on fire, my friend in TX meets many online friends and has had mixed results ... sure have fun but get to properly know the person on the other end of that connection too, a little friendly caution never hurt anyone.