That the Internet can be both amazing and dangerous is common knowledge, unless you're a pre-teen, in which case you might need to see a real-life example to properly understand.

Vicky Walker, who teaches 10 and 11-year-olds in Scotland, wanted to show her young charges how widely a photo can spread once placed on Facebook, so she posted the handwritten plea you see here to her own account on Jan. 13. As of this morning, the photo has been shared 163,000 times on Facebook alone, viewed in 90 countries, and, she's been told, even seen on the International Space Station.

Lesson No. 1 accomplished.

Reaction from her students, Walker tells me, "has been amazement and also horror at how lax privacy settings on Facebook can be (a lot did not know about having to change privacy settings on individual photos, for example)."

Lesson No. 2? As if on cue, the ugliness of the Internet reared its trollish head.

"Since running the experiment I have gotten many emails of support," she says, "but also some rather vicious ones, including an incident today where someone impersonated me on Facebook, added all of my current friends and posted things that I wouldn't say on that profile."

"I was able to get the fake page taken down after providing evidence to Facebook and I will tell my children about it happening," she says. "I want them to know the full dangers of the Internet, social media and cyber-bullying."

Walker says she reminded her students that they are as yet too young to meet Facebook's 13-year-old age requirement, but she knows that hasn't stopped a number of them. "If they are going to use social media, I wanted them to be aware of the dangers out there. This experiment has also really hit that home for me."

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Obviously, there is nothing remotely scientific about Walker's experiment; it was just a simple demonstration. And, victim blamers will blather that Walker invited the impersonation trouble by posting her request to the general public.

But her students will undoubtedly get the message. And, my own three 12-year-olds heard all about it at the dinner table last night.