mischief-making 
noun [mass noun]
The action of deliberately creating trouble for other people.It reflects more than the senator's indisputable propensity for mischief-making....
- They all hopped in the tub for a big, bubbly family bath, and then the mischief-making got underway as they bounced on the bed in their matching bathrobes - a surprise gift Amy had bartered for on-line.
- Again, though, the Internet makes the costs of mischief-making so low, even if there's no profit motive, that its proliferation becomes inevitable.