The subject of an urban legend, that rub-on "tattoos" of blue stars, available in schoolyards, are laced with LSD and possibly strychnine that will kill your child.
The legend dates back at least till the 1970s and has appeared in several forms, often replacing the blue-star motif with superheroes or cartoon characters. Any tale about a threat to kids, of course, however silly, tends to spread like wildfire. Schools, preferring to be safe than sorry (and seeking to limit liability) put out warnings to parents, newspapers and TV stations acquire copies of the warnings and do stories, local politicians get involved, the police check it out...
This particular legend, however, is fairly obvious nonsense:
- LSD is not easily absorbed through the skin.
- It's not cut with strychnine.
- If you're a drug dealer, putting out samples of a non-addictive drug for free is a peculiar strategy.
- If you're a mad poisoner, why the acid?
There are no verified cases of this happening, or anything like it.