Recently I've had my first hacked problem: 372051449. I didn't really think much of hacking up until this point, but this problem made me rethink. I have a few questions in mind:

1. What type of problems are most likely hackable?

2. What are the general methods used to hack a submission?

3. What preventive measures can be taken to protect a solution from hacks?

I'm interested in your ideas about hacking. Feel free to drop a comment!