If 8chan was recruiting people to join al queada in Syria, we wouldn't even be having this conversation. They're a terrorist recruitment site, full stop. Shut them down.
To anyone who can understand Urdu or Hindi, it's trivially easy to find speeches of terrorist leaders on YouTube. Hundreds of thousands of people have watched instigating speeches of Masood Azhar, Ilyas Ghuman, Israr Ahmad, hundreds of thousands of "likes" on the videos, thousands of appreciative comments.