It's a setting in CodeMirror which jsbin and jsfiddle both make use of.
However, if you open the devtools console in your browser, and run: `jsbin.settings.editor.smartIndent = false` it'll disable the indenting. The setting is sticky, so you it should remain whilst the data is stored against the browser.
Not yet, but there will be. For the moment, anything you can set in CodeMirror's config ( http://codemirror.net/doc/manual.html#config ) you can set via `jsbin.settings.editor.[key] = [value]` and it'll apply it to the JS Bin editors.
There's a couple of others, and docs will be coming soon. In addition, there's an exposed API that allows you to point JS Bin to a JSON file and it'll load in and save those settings - which is useful for starting a class for teaching where you want the editor in the same mode across all the students.
However, if you open the devtools console in your browser, and run: `jsbin.settings.editor.smartIndent = false` it'll disable the indenting. The setting is sticky, so you it should remain whilst the data is stored against the browser.