When I attempted to load this image - http://min.us/ldm9KG - I get an error:

Exception happened during processing of request from ('127.0.0.1', 49311) Traceback (most recent call last): File "/home/vfdc/src/mediagoblin/eggs/Paste-1.7.5.1-py2.6.egg/paste/httpserver.py", line 1068, in process_request_in_thread self.finish_request(request, client_address) File "/usr/lib/python2.6/SocketServer.py", line 320, in finish_request self.RequestHandlerClass(request, client_address, self) File "/usr/lib/python2.6/SocketServer.py", line 615, in init self.handle() File "/home/vfdc/src/mediagoblin/eggs/Paste-1.7.5.1-py2.6.egg/paste/httpserver.py", line 442, in handle BaseHTTPRequestHandler.handle(self) File "/usr/lib/python2.6/BaseHTTPServer.py", line 329, in handle self.handle_one_request() File "/home/vfdc/src/mediagoblin/eggs/Paste-1.7.5.1-py2.6.egg/paste/httpserver.py", line 437, in handle_one_request self.wsgi_execute() File "/home/vfdc/src/mediagoblin/eggs/Paste-1.7.5.1-py2.6.egg/paste/httpserver.py", line 287, in wsgi_execute self.wsgi_start_response) File "/home/vfdc/src/mediagoblin/eggs/Paste-1.7.5.1-py2.6.egg/paste/urlmap.py", line 203, in call return app(environ, start_response) File "/home/vfdc/src/mediagoblin/eggs/Beaker-1.5.4-py2.6.egg/beaker/middleware.py", line 152, in call return self.wrap_app(environ, session_start_response) File "/home/vfdc/src/mediagoblin/mediagoblin/app.py", line 115, in call return controller(request)(environ, start_response) File "/home/vfdc/src/mediagoblin/mediagoblin/decorators.py", line 50, in new_controller_func return controller(request, args, **kwargs)File "/home/vfdc/src/mediagoblin/mediagoblin/submit/views.py", line 79, in submit_startprocess_media_initial.delay(unicode(entry['_id']))File "/home/vfdc/src/mediagoblin/eggs/celery-2.2.6-py2.6.egg/celery/task/base.py", line 338, in delayreturn self.apply_async(args, kwargs)File "/home/vfdc/src/mediagoblin/eggs/celery-2.2.6-py2.6.egg/celery/task/base.py", line 436, in apply_asyncreturn self.apply(args, kwargs, task_id=task_id)File "/home/vfdc/src/mediagoblin/eggs/celery-2.2.6-py2.6.egg/celery/task/base.py", line 597, in applyretval = trace.execute()File "/home/vfdc/src/mediagoblin/eggs/celery-2.2.6-py2.6.egg/celery/execute/trace.py", line 76, in executeretval = self._trace()File "/home/vfdc/src/mediagoblin/eggs/celery-2.2.6-py2.6.egg/celery/execute/trace.py", line 86, in _tracepropagate=self.propagate)File "/home/vfdc/src/mediagoblin/eggs/celery-2.2.6-py2.6.egg/celery/execute/trace.py", line 34, in tracereturn cls(states.SUCCESS, retval=fun(*args,**kwargs))File "/home/vfdc/src/mediagoblin/eggs/celery-2.2.6-py2.6.egg/celery/task/base.py", line 241, in *call*return self.run(*args, **kwargs)File "/home/vfdc/src/mediagoblin/eggs/celery-2.2.6-py2.6.egg/celery/app/**init*.py", line 141, in runreturn fun(args,*kwargs) File "/home/vfdc/src/mediagoblin/mediagoblin/process_media/init.py", line 45, in process_media_initial thumb.save(thumb_file, "JPEG") File "/usr/lib/python2.6/dist-packages/PIL/Image.py", line 1439, in save save_handler(self, fp, filename) File "/usr/lib/python2.6/dist-packages/PIL/JpegImagePlugin.py", line 425, in _save raise IOError("cannot write mode %s as JPEG" % im.mode) IOError: cannot write mode P as JPEG

There's no way around it, we're going to need a good sanitizer for comment/description/etc html regardless of whether or not we use markdown ... so I think the html cleaner should:

• use lxml.html.clean
• Use only whitelisted tags... this is possible through lxml, we need to do it right. Tags I think we'll need to allow: b, i, em, strong, p, ul, ol, li, a, br. (any others?)
• Only whitelisted attributes
• XSS attribute attack prevention, other XSS prevention stuff... see the lxml.html.clean docs.
• have tests that try to attack each one of these components.

In the future it might be a good idea to also prevent certain other annoying things... deeply nested

.. raw:: html

   <p>

's, etc. But for now I think this will be good enough.

At some point, we will need to address exif data. I think it would be nice for the user to be able to access and search for their exif data, but we also want to be able to let the user scrub it before posting to their network. The best case is where the user has access to exif data by default and the viewer does not.

Usecase 1: I want to search for all the photos from my trip to Greece 4 years ago using my exif data.

Usecase 2: I do not want people to access the exif info for my kid's elementary school or my company's colo.

Usecase 3: I want to see the exif info for last year's awesome mushroom foraging spot, but absolutely do not want it made public.

Finely tuned control of exif data would represent a tangible feature that we could offer that is not offered by flickr. I don't have a strong opinion about how this would look on the back end. On the front end it should be very clear what's happening and the default should be to strip it out before posting so no one posts exif data unless they specifically choose to.