I see both sides of the coin here.

When I first told a friend of mine that I was cutting myself, he wanted to throw my knife away. But the thing is, throwing away the cutting tools will only stop the symptom, but won't cure the "disease". The anxious/depressed/borderline/etc thoughts will still be there. Plus, we can find -anything- to cut with. Months later, I threw away my razor and cutting scissors as I thought I had put my self-harm behind me. But a few weeks after throwing them away, I found myself with an overwhelming urge and used my regular scissors. Plus, everyone has fingernails and teeth that they can use to self-harm with. So, I understand the good intentions behind it, but it doesn't solve anything. IMO the tools should be thrown away once the person who self-harms is ready for it.