It's easy to set up your own (free) button server though. Here's how: https://bountify.co/blog/host-your-own-hacker-news-button-se...
I honestly didn't realize how much traction it picked up over the past 6 months.. It was a (pleasant) surprise to login into my GAE console and realize that it was serving, on peak days, over 1M impressions.
Interestingly enough, the "exceeded quota" was not for CPU resources! Instead, it was all egress bandwidth. On busy days, it would reach the free 1GB egress limit sometime between 6-12PM, and hence the error. I've upgraded the app, and it should be good for terabytes a day. ;-)
P.S. I've also pushed an update to enable more aggressive HTTP caching on the assets.
"But how do you know if you're logged into HN?" Ah, that's the hack.
for example: https://hacks.mozilla.org/2011/02/an-interesting-way-to-dete...
more in depth: http://stackoverflow.com/questions/5233560/possible-to-find-...
For example, maybe posting a blank password to "change password" form will return a non-success status code when you aren't logged in, and be an innocuous post (since it results in an error).
Of course, the trouble with these techniques is that the site can disable them at any time.
Edit: You can style ".hn-share-iframe". Then the next issue: it's much wider than it needs to be when the story has already been submitted (see the screenshot, there's a lot of blank space on the right). Is there any other solution besides just positioning it on the right of the share buttons list?
EDIT: This is a submission from a while ago that does, in fact, upvote itself.
They all show "submit". I re-submitted one of the stories myself. Still shows "submit" as the HN button.
EDIT: Ok apparently it does work after I submitted a story through it (cold cache?) But it's still pretty meh, really just a glorified <a><img></a>
On a side note. Could someone at YC fix the up vote arrows here? It's really hard to hit these tiny arrows without hitting everything around before, really messy. BTW, a larger textfield wouldn't hurt either.
PS: Sorry for stealing your topic, I just felt the need to say these things which I think don't bother only me. ;)