I host 4 forums and do not have allot of room for attachments. It is interesting how simple some things must be for people to post in there thread that they need the simplicity of attachments. Damn if they are not willing to clean up there own space.
Honestly, attaching files to the forum thread vs. using a hosted solution is more stable and 'better' long term IMO. Google Photos/Picasa has a history of refreshing/regenerating the hosted picture links which destroys threads in an instant without anything to do with the forum. Photobucket, heck they all do, has done the same thing. Its a 'pick your poison' decision.
Attachments & Avatars were broken when I moved us to fresh copy of SMF. We were on a locked down/crippled version that 1&1 promotes as a quick and easy way to host a website/forum without having to know anything about the technologies that support it. Pretty sure my bin/ASCII flag was wrong when I did the migration, but it was too late to fix it when I figured it out...would have lost new data to do it.
However, that move allowed us to add several plugin's that have (knock on wood) so far kept the spammers/hackers at bay, and at the same time, allowed us to stay current on security patches.
We all know its only a matter of time...we will get hacked at some point as nothing is secure on the internet. We can only plug the holes as patches are issued and block IP's we don't like...and we have entire portions of the world blocked at this point.