carriers

Yeah, I don't get this at all. I think it's even deeper than designing for controversy. I'm "older" (40s), though I work on products used by younger people, so I don't think this is just me being old, but I can't follow a conversation on twitter at all. When there's a link from HackerNews to Twitter, I click on it and sometimes see the thing mentioned in the HN title, and sometimes don't. Then there's a bunch of stuff below it, some of which is definitely replies to the original post, and some of which appears to be part of a completely different conversation. Some threads of conversations get cut off for no apparent reason and you have to click something to see more of them. Nothing is indented, so it's really hard to tell who's replying to whom.

I basically can't understand a thread on Twitter, so I've never signed up because who the hell wants to be part of that? I usually also don't go to Twitter to read stuff other people link to because I'm not going to be able to follow it. Forget boosting controversial stuff, I bet a lot of users post the way they do because they also don't understand what they're looking at.

It's at the carrier level. I believe that at least some part of it is noticing that the calling number is a number that doesn't exist. For example AT&T might be given phone numbers 555-0000 through 555-1000, and they know they've only actually given out 555-0000 through 555-0782, but the caller ID claims the number is 555-0999. They can tell it's not a legitimate call because that number couldn't be making an outgoing call because it's not assigned.

I don't think that's all of it by any means, but there are a number of ways that the carriers can tell that some percentage of the calls are bogus without having to ask the receiver if they want to receive it.