Practical tip for parents here struggling with the problem of 'distractions during school hours': use a DNS filtering service.<p>I use the Family package from SafeDNS and I'm generally happy. It is also cheap at $20/year. I like SafeDNS because they provide a Desktop client that prevents tampering.<p>You can configure different profiles such as 'Education', 'Creative' and 'Default' for different modes you want to put your child's computer on - remotely. So during schooling hours I configure their computers to be on 'Education' mode, but if they want to just do Scratch or some other brain-stimulating activity, I put it on 'Creative' mode. For free time I'll put it on Default which I've configure to allow YouTube.<p>I configure each profile to block preconfigured vendor-supplied site archetypes such as Videos, Gaming, Advertising, Shopping, Chat etc. I have full control over each profile type. I can also whitelist a domain if they get in a snag.<p>I'm sure there are other good DNS filtering service providers, but this one is the one that worked best for me.