current silo support:

• Twitter: yes, via search. we already do this to walk reply chains.
• Google+: kind of. i tried activities/search for finding the +Trisha Weir mention in this post. it didn't work with "+Trisha Weir", +Trisha Weir, https://plus.google.com/+TrishaWeir, or https://plus.google.com/106299364027673376307, but it did work with "Trisha Weir". that query will technically return posts that just have people's names without mentioning them, which means we'll get some false positives, but maybe in practice that's ok. not sure.
• Flickr: no. Flickr only has people tags (backfeed person tags (especially on photos) to the original posts #488), not mentions.
• Facebook: no. Not via notifications: They can only be read for pages, not for users. A number of other endpoints look promising, but don't pan out. Google doesn't find much either. and FB removed search from the API in v2.0 (see search all silo posts for links to users' sites and send mentions #456).
• Instagram: no. search is just for location, not text query.

one wrinkle here if that twitter @-replies usually mention the tweet's author, but they probably shouldn't get backfed to the front page as mentions.

however, if someone mentions you in a reply to someone else, that maybe should get backfed.

here's a straw man: if a mention isn't a reply, backfeed it. if it is, but it's not a reply to you, and if the tweet it's replying to doesn't mention you, backfeed it.

(other silos don't start comments with mentions by default, so they don't have this problem.)

I'm ok with not doing the backfeed a second time for posts that are a direct reply to you. But I'd also be ok with doing it, since it still mentions you. Either way.

sounds good!

i'm also inclined to suppress mention backfeed when we find an original post link to one of your sites, e.g. tweets like these, so that we don't double backfeed those either.

turning this on now. hold onto your britches...

first confirmed kill!
https://brid.gy/twitter/leitmedium#responses
https://twitter.com/nordhessenmami/status/668539086567809025

(their site doesn't accept front page webmentions, but that's fine.)

example of one that did go through:

https://twitter.com/lucavgobbi/status/668762681000796160
http://www.kevinmarks.com/

(i love how @kevinmarks's use of webmention.herokuapp.com on his front page is kind of a light stress test. :P)

getting these now but they don't actually refer to my URL, for example
it sent me a webmention of https://brid-gy.appspot.com/post/facebook/14305603/837135243002270 pointing to https://ben.thatmustbe.me/
but my homepage URL is missing from the generated page