allow refs/heads/users/* only to known non-troll users
diff --git a/groups b/groups
index 0c684a4..57894d2 100644
--- a/groups
+++ b/groups
@@ -3,6 +3,7 @@
 147b3de9543270b1b23526883b1bf91ec5ad42a0	Administrators
 2711f8677a316d19c7f15f30bcf25c2ffb706ead	Non-Interactive Users
 b588ccf0327cd98b42a4ac07213796de29f6205b	sysmocom branch access
+f3f46fd3a6951dd36adfab6c1a6ebfced2d45e78	known users
 f4d0b57d31558a3f33e2199e3f75d2900b1ff638	Reviewers
 global:Anonymous-Users                  	Anonymous Users
 global:Project-Owners                   	Project Owners