About 12 years ago I sent an anonymous email. As I typed that devastatingly romantic Valentine message, I felt a strange kind of thrill. After all, this was something I would never have dared to say in person.

But as soon as I sent it, I felt curiously deflated. I would have no idea of her reaction, and she would have no idea who'd written it. I should have felt unburdened, but instead I felt ashamed of my pathetic inability to deliver a compliment.

A bunch of anonymous emails were received by journalists and bloggers a few days ago. They were intended to promote a new service which facilitates the sending of such, but as a PR stunt it was pretty clumsy, creating as it did a certain amount of paranoia and unease, thus instantly flagging up the service's drawbacks. Forced on to the back foot, its founder explained that this was a "really positive and exciting tool", and when pressed further on its negative qualities he replied that this "really isn't what the product is about – it's about saying the truth you're ashamed to say".

There are a number of new anonymous services knocking about that sell themselves as facilitators of that "truth". Secret and Whisper are the main ones, but they both serve as a kind of overflow pipe for Twitter and Facebook, enabling the kind of bragging or complaining that people would normally be reluctant to put their names to. As they're publicly visible, boasts of sexual conquests, spleen-venting and self-pity are endemic, and I suppose there's a school of thought that might consider that to be liberating, or a more "authentic" form of social media.

But anonymous emails are different, because they're private. If you anonymously say something unpleasant to someone, you're a coward – but as I discovered, if you anonymously say something complimentary, you're also a coward. The founder of this particular service says that he believes in "providing a tool to connect with people on a more candid and personal level", but a) it's not personal, and b) why does he believe that we're not already connecting candidly enough? Perhaps he's trying to drag us toward some kind of social utopia that I don't fully comprehend, but I know that human beings understand that there are limits to candour, because we've been negotiating them for millennia.

We also know that anyone who proudly claims that they "tell it like it is," that they "speak as they find" or "don't mince their words" is generally a bit gittish, but it's precisely that kind of untrammelled splurging of ill-considered thoughts that this service encourages.

In an age of excessive online information, ignoring any unattributable messages would seem like an excellent place to start trimming fat, so I've sensibly put an email filter in place to send these anonymous messages winging their way up the arse of nowhere.

I can't quite bring myself to name the service because it doesn't deserve the publicity that it thinks it does. But it's part of a trend where apps and services prod and poke at aspects of human nature that are probably best left alone.

It's naive to expect the creators to morally rein themselves in, but we should understand what they are – social experiments dressed up as entertainment – and laugh out loud at claims that they're somehow benign. In this particular case, the service even provides a long list of "dos and don'ts", presumably to absolve itself of responsibility when cruelty and unpleasantness rear their heads.

Nota bene: if you have to construct an etiquette guide that preempts the ways in which your service can be abused, you probably know that it's less of a service and more of an exercise in self-publicity.