alt Hacker NewsI helped my friend from university get a job by helping him do their take-home exercise. I didn't write the code for him but I walked him through pretty much every single step. I'm not proud of that but my friend needed a job and I was in a position to help him get it. My principles are not nearly as important as that job was to him.
If you let people cheat they will cheat.
Yes, people can cheat. In my example, you can mitigate by having them also do a live presentation and ask probing questions about what they've written if that's part of the job.
The coding equivalent would be asking them why they took some specific approach or used a particular algorithm. I'm not sure about my feelings with respect to coding takehomes but there are circumstances where someone doesn't have an openly viewable body of work where takehomes can make sense.