Personally (and this may not be a very popular opinion) I do believe they should be banned.
This isn't to say that it will stop eating disorders from happening OR that it would be possible to entirely ban thinsporation. After all, the internet has a lot of damaging stuff on it.... but I truly do believe in boundaries.
After all, if there were no regulations then where would our own moral/social/political boundaries be? Is it ok to do whatever the hell we like online simply because it doesn't have the same social-consequences as 'real life'?
If the argument that we shouldn't have any sort of censorship be taken literally then what about issues such as pornography? Is it ok to portray sex even if it's non-consensual? What if it was damaging to the parties involved? What if it encourages children to have sex? Is that ok?
Im not saying that thinsporation is the worst thing you could do on the internet, but we can't live in a world with no boundaries. And encouraging people (young and old, male and female) to starve - or cut or commit - isn't ok with me.
By all means raise awareness of eating disorders (self harm, suicide etc) but dont glamourise it on the way! You don't have to sensationalise mental health problems.