This whole debate centers on the fact that the website is at fault, and that is something everyone has pretty much already decided. The father of the victim has claimed the owners of ask.fm should be charged with murder, which is just ridiculous.

Any website which promotes, glorifies, or encourages bullying should be punished (definitely not with a charge of murder), but it would be fair game for a boycott or loss of advertising revenue. Ask.fm does in fairness provide a fairly easy platform for people to bully you, since it is all anonymous, but then so does any other social media site. The website has a duty to do as much as they can to stop abuse, but then so do the users themselves. No one is forcing you to have an ask.fm profile, or indeed engage with it.

If we look to Lawrence Lessig's four modalities of regulation, up until this point, ask.fm has relied on the social norm of users not making hurtful comments to other users. Advertisers pulling out is a form of regulation by the market, but it will hurt the site, not the offending users, and I believe the site does as much as it can to stop bullying. Removing some of their revenue won't stop the problem unless they shut the whole site down because they run out of money.