An admin might want to check what another user is running using screen. The best you can see even as root using ps, is just the name of the command, like below:

sudo ps awxuf | grep -i screen
 
root      1135  0.0  0.0  13636   976 pts/1    S+   13:27   0:00                          \_ grep --color=auto -i screen
john   4245  0.0  0.0 387364 16668 ?        Sl   Feb02   0:06  |       \_ gnome-screensaver
1001      6762  0.0  0.0 347384 10428 ?        Sl   Feb02   0:00              \_ gnome-screensaver
john    625  0.0  0.0  31320  1568 ?        Ss   11:57   0:00 SCREEN -S test

pstree -Gap 625
 
screen,625 -S test
 
  └─bash,626

When you try to access the screen session using other user, this is usually the error:

sudo -u john screen -r 625
 
Cannot open your terminal '/dev/pts/1' - please check.

This is because, your terminal: /dev/pts/1 is only readable and writable to the owner of the terminal:

ls -lh /dev/pts/1
 
crw--w---- 1 john tty 136, 1 Feb  12 13:30 /dev/pts/1

To overcome this, simply allow read and write to the terminal, to all users:

chmod o+rw /dev/pts/1
ls -lh /dev/pts/1
 
crw--w-rw- 1 john tty 136, 1 Feb  12 13:32 /dev/pts/1

Once that done, you can use sudo to access the screen of the other user:

sudo -u john screen -r 625