shadowban effects as of 1st of October:
1) tweets don't appear in search (web/tweetdeck)
  a) this also applies to attempts to search for tweets quoting s/banned tweets, via the search string "twitter.com/(username)"
  b) this does not apply to searches for replies to s/banned users, via the search string "(username)" or "@(username)"
2) multi-tweet threads don't work (web/tweetdeck)
3) replies to s/banned user invisible (tweetdeck only)
4) a reply to s/banned tweet doesn't show the parent tweet (web/tweetdeck)
  a) except: a reply to a top-level s/banned tweet (that is, a tweet that is not itself a reply) shows the parent tweet – on tweetdeck only
5) "tweet unavailable" shown in the middle of longer threads, but only in place of tweets occurring after the tweet in focus (web only)
6) in longer threads, tweets occurring before the tweet in focus are omitted without any indicator (web/tweetdeck)
7) quoted s/banned tweets are not loaded and must be clicked to be viewed
8) notifications of interactions with s/banned users don't appear, or appear and then disappear

non-effects:
1) tweets are visible from s/banned user's own page
2) direct links to individual tweets still work, even reply-tweets, which are otherwise hidden except on the s/banned user's page