(this section is a stub and needs your contribution to complete it!)
Exporting your data
Instagram does not have a photo upload API. However they do have comments delete / create APIs. So here's how you can fake POSSE to Instagram:
And bingo, you've effectively created a POSSE copy of your photo on Instagram since it now has a permashortlink back to the new "original" on your own site.
Manual Notes POSSE
Some users manually POSSE occasional notes posts to Instagram, e.g.:
As of this edit:
For some reason, POSSE copies, even of *notes*, on Instagram receive more interactions per follower.
Hypothesis: the Instagram reader experience is so much smoother and nicer that it tends to encourage more use and thus more interactions.
Supposed Features and Limitations
Ryan Barrett has found that Instagram's API now supports progammatically "liking" photos (used to 400).
Ryan Barrett has found that authing with scope=comments works, but the API call still 400s.
Bad Silo Interop with Twitter
Shortly after it was purchased by Facebook, Instagram stopped including Twitter metadata on their photo pages, so Twitter Cards no longer show image previews for Instagram photos.
Instagram drives more traffic to their site, at the cost of a worse experience for users.
Using OwnYourGram or another method of PESOSing your photos out of Instagram, you can control how your photos are shared on other silos like Twitter. (e.g., by including Twitter metadata, or by posting the photos directly).
Switch from Foursquare to Facebook venues
This has resulted in:
Lack of privacy of location data
When posting a photo to Instagram, if "add to photo map" is enabled (even if no venue is chosen) then the exact lat/lng of the photo is recorded. When viewing the single photo you won't see the location of it. However, when viewing the person's user profile you can switch to the map view and see their photos all on a map.
The map shows photos as clusters, and zooming in will expand the clusters into smaller clusters until finally individual photos appear on the map.
It is relatively easy to figure out the approximate location of someone's work or home by looking for these clusters.
Uneditable Custom Locations
When adding a photo at a venue that doesn't exist, it is possible to create a "custom location", which is unfortunately not editable from that point on.
One potential up-side is when searching for venues, your custom locations now show up at the top of the list without needing a round-trip to the server to search.
Creating this custom location prompts only for the name, the exact geo location is added automatically, meaning it is not possible to adjust the specific location of the venue.
Censorship beyond community guidelines
Instagram is establishing a history of censoring by removing (and sometimes restoring later) and/or hashtag results that are not actual violations of their Community Guidelines, and are otherwise innocuous material. For example:
No license metadata
Unlike Flickr (and your own site if you so choose!), there's no metadata for marking photos or indeed whole photostreams as licensed under Creative Commons licenses.
i-am-cc.org lets you choose a CC license for your Instagram photographs, but you have to log into the service every three months to 'renew' the license grant.