5 ms·

How does Youtube detect adblock anyway? Is that documented anywhere?

by dale_glass 3y ago

Dwedit 3y ago
It's not very hard to see when particular web requests did not happen, or particular JS did not execute.
- blibble 3y ago
  you can make the request and hide the result from the user
  - tekla 3y ago
    Which defeats about 75% of the reason to use the adblocker.
    - impeplague 3y ago
      In the specific case of YouTube, it does not. The content and ads providers are the same.
    - graphe 3y ago
      I'd say closer to 99.9999% of users who can stream YouTube aren't trying to save data and just want to AdBlock.
    - blibble 3y ago
      if there's no other option it's a still infinitely better than seeing HOT SINGLES IN YOUR AREA or another MANSCAPED ad if it gets to that point I wouldn't mind the adblocker even automatically clicking the ad some percentage of the time, just to punish Google
      - fxtentacle 3y ago
        That's called AdNauseam.
        blibble 3y ago
        not quite I don't want to punish everyone, only those attempting to coerce me into disabling the ad-blocker
  - pavon 3y ago
    For something like YouTube it can probably still be detected by timing. If the browser plays part A of a video, then when it is done immediately requests part B of the video, when there is supposed to be a 2 minute gap to play an ad, that can be detected on the server side. The client could try to get around that by doing things like telling the server it is playing at 2x, and then really playback at 1x, but then the server could send different content (pre-downsampled) depending on the playback rate requested.
- dale_glass 3y ago
  That doesn't seem to be what is happening, because then uBlock Origin couldn't work around it. Also things like Newpipe and embedding can be used to bypass the block as well. I find all of this weird because it seems all so lacking in fundamentals. I'd expect indeed checking whether the content was actually downloaded. That'd be much harder to work around. In turn that should result in an ad blocker that downloads content but doesn't show it, completing the circle. I think properly doing it would require a specialized web browser, capable of keeping two separate models, one which it pretends to render, and one which is actually renders.
  - mrguyorama 3y ago
    It is beneficial for Google to drag out any cat and mouse game against ad blockers as long as possible. They are all built and maintained by volunteers, who get yelled at by assholes every time something changes and breaks an ad blocker even for a single night. Google is trying to make this suck for the maintainers, explicitly so they stop maintaining the ad blocker.
kleiba 3y ago
There was an article posted on that topic here a few days ago: https://news.ycombinator.com/item?id=38061187 https://news.ycombinator.com/item?id=38061187
codybontecou 3y ago
I read somewhere Youtube used to send a response like {..., ads: [1, 2, 3]}. uBlock would see this response and turn it into {..., ads: []} and load the page accordingly. I guess now, Youtube expects a response back, and occasionally, the request/response is faked. So, when uBlock adjusts the request/response and says "This user watched the ads", Youtube knows the request/response was fake and there were no ads to begin with, notifying that user is using an adblocker.
- krackers 3y ago
  Looking at the filters that uBlock is using, it still seems to be some sort of regex on the xhr request/response body [1]. Why can't youtube trivially defeat this by encrypting everything? It seems like trying to go about the cat-mouse game in this fashion in a losing battle, because all google needs to do is just change up the names a bit each day. [1] https://github.com/uBlockOrigin/uAssets/commit/fb33bb3c1fa99db4be4e7a3e9f76ecfe58a25444 https://github.com/uBlockOrigin/uAssets/commit/fb33bb3c1fa99...
  - LelouBil 3y ago
    > It seems like trying to go about the cat-mouse game in this fashion in a losing battle, because all google needs to do is just change up the names a bit each day. That's exactly what they are doing, well I don't know about only "change up the names" but they update the script multiple times per day and uBlock Origin devs are trying to catch up.

How does Youtube detect adblock anyway? Is that documented anywhere?

Dwedit 3y ago

It's not very hard to see when particular web requests did not happen, or particular JS did not execute.

blibble 3y ago
you can make the request and hide the result from the user
- tekla 3y ago
  Which defeats about 75% of the reason to use the adblocker.
  - impeplague 3y ago
    In the specific case of YouTube, it does not. The content and ads providers are the same.
  - graphe 3y ago
    I'd say closer to 99.9999% of users who can stream YouTube aren't trying to save data and just want to AdBlock.
  - blibble 3y ago
    if there's no other option it's a still infinitely better than seeing HOT SINGLES IN YOUR AREA or another MANSCAPED ad if it gets to that point I wouldn't mind the adblocker even automatically clicking the ad some percentage of the time, just to punish Google
    - fxtentacle 3y ago
      That's called AdNauseam.
      - blibble 3y ago
        not quite I don't want to punish everyone, only those attempting to coerce me into disabling the ad-blocker
- pavon 3y ago
  For something like YouTube it can probably still be detected by timing. If the browser plays part A of a video, then when it is done immediately requests part B of the video, when there is supposed to be a 2 minute gap to play an ad, that can be detected on the server side. The client could try to get around that by doing things like telling the server it is playing at 2x, and then really playback at 1x, but then the server could send different content (pre-downsampled) depending on the playback rate requested.
dale_glass 3y ago
That doesn't seem to be what is happening, because then uBlock Origin couldn't work around it. Also things like Newpipe and embedding can be used to bypass the block as well. I find all of this weird because it seems all so lacking in fundamentals. I'd expect indeed checking whether the content was actually downloaded. That'd be much harder to work around. In turn that should result in an ad blocker that downloads content but doesn't show it, completing the circle. I think properly doing it would require a specialized web browser, capable of keeping two separate models, one which it pretends to render, and one which is actually renders.
- mrguyorama 3y ago
  It is beneficial for Google to drag out any cat and mouse game against ad blockers as long as possible. They are all built and maintained by volunteers, who get yelled at by assholes every time something changes and breaks an ad blocker even for a single night. Google is trying to make this suck for the maintainers, explicitly so they stop maintaining the ad blocker.

kleiba 3y ago

There was an article posted on that topic here a few days ago: https://news.ycombinator.com/item?id=38061187 https://news.ycombinator.com/item?id=38061187

codybontecou 3y ago

I read somewhere Youtube used to send a response like {..., ads: [1, 2, 3]}. uBlock would see this response and turn it into {..., ads: []} and load the page accordingly. I guess now, Youtube expects a response back, and occasionally, the request/response is faked. So, when uBlock adjusts the request/response and says "This user watched the ads", Youtube knows the request/response was fake and there were no ads to begin with, notifying that user is using an adblocker.

krackers 3y ago
Looking at the filters that uBlock is using, it still seems to be some sort of regex on the xhr request/response body [1]. Why can't youtube trivially defeat this by encrypting everything? It seems like trying to go about the cat-mouse game in this fashion in a losing battle, because all google needs to do is just change up the names a bit each day. [1] https://github.com/uBlockOrigin/uAssets/commit/fb33bb3c1fa99db4be4e7a3e9f76ecfe58a25444 https://github.com/uBlockOrigin/uAssets/commit/fb33bb3c1fa99...
- LelouBil 3y ago
  > It seems like trying to go about the cat-mouse game in this fashion in a losing battle, because all google needs to do is just change up the names a bit each day. That's exactly what they are doing, well I don't know about only "change up the names" but they update the script multiple times per day and uBlock Origin devs are trying to catch up.