People:

The penny sticks! I broke the matrix!1!!

Scientists:

Interesting. But instead of jumping to conclusions, let's examine a few questions first:

1. Does it works with different materials?
2. Does it work with different walls?
3. Does it work with different paint on the wall?
4. Is there a magnetic field?
5. Could it have something to do with electrical wires inside or behind the wall?
6. Does it work when electricity is shut off?
7. Does it work inside a faraday cage?
8. Does it work outside?
9. Does it work on living things, like trees?
10. Does it work when I think differently?
11. Does it work with different people?
12. Does it work when different people think differently?
13. Does it work under water?
14. Does it work in the vacuum?
15. Does it work in space?
16. What conditions are necessary to reproduce the effect?
17. What conditions can cancel the effect?

The fact that many grown up adults don't even ask one of those questions first is... disturbing.