Alex Brollo wrote:
I'm happy from this since I currently use hotlinking from Commons into web communities, forums and so on. More, if I have some interesting personal picture to share into a community, and I presume that such a picture could be useful to any other user of the web here or there into the net, I usually upload it into Commons then I hotlink it. So, a "free hotlink policy" can directly encourage upload into Commons; nevertheless a good categorization (a very difficult aim) is mandatory, and this aim could be difficult to obtain when the uploader is mainly interested to hotlink his uploaded file. So, while encouraging "free hotlink policy", I advocate any effort to ameliorate categorization and to make it easier and easier.
-- Alex
We shouldn't encourage hotlinking. Technically, it's not an issue but you shouldn't consider it a "supported" usage either. Basically, you're on your own.
Although most images are kept invariant and we try not to break the links, images *do* get deleted/renamed. You have no guarantees that the image won't get deleted (specially if you're the uploader and it's not a educational image). Moreover, the content of your blog/posts could be modified by uploading a new image over the one you use. We strive to avoid image vandalism, but after all, this is a wiki. And your readers expectation will be that it's the image you originally wanted to link to, not that it's a wiki-modifiable image.
If you're hotlinking from your web, you should copy the image and include the image that is on your web space (you can link to the image page for more versions, license compliance, etc.).
If still want to hotlink commons images, you should *Enable email notification on your preferences http://commons.wikimedia.org/wiki/Special:Preferences when you get a message on your talk page. This way you won't miss a notification about a delete request for an image you uploaded.
*Watchlist the images you use. This way you can from time to time view http://commons.wikimedia.org/wiki/Special:Watchlist and verify nothing nasty has happened to those images.
(You can also opt to receive an email when there're changes to those pages)