Pistons can be activated by putting a torch or redstone block one block above using a block beside(see picture)

*What I expected to happen was the piston to not extend

*What actually happened was the piston became powered and extended

Steps to Reproduce:
1. Put a piston facing upwards on the ground
2. Place a block beside the piston
3. Put a torch on top of the block

Was found in version 1.5.2