Some interesting options

1 Hide processes running as other users

The proc filesystem supports the following mount option hidepid

0 Everybody may access all proc[pid] directories. This is the traditional behavior, and the default if this mount option is not specified. 1 Users may not access files and subdirectories inside any proc[pid] directories but their own (the proc[pid] directories themselves remain visible) 2 As for mode 1, but in addition the proc[pid] directories belonging to other users become invisible.

mount -o remount,rw,nosuid,nodev,noexec,relatime,hidepid=2 /proc
proc    /proc    proc    defaults,nosuid,nodev,noexec,relatime,hidepid=2     0     0

2 Disable reading kernel message buffer for unprivileged users

sysctl -w kernel.dmesg_restrict=1