I have changed the ownerships of $HOME and subdirectories to only have default "owner" and "group" permissions using the following command:

~$ chmod o-rwx -R ./* ./.[!.]*
Can this potentially cause any issues?

Background: I have several users on the same machine, and would like to isolate their documents and workspaces from each other.
Each owner has an own group like: tom:tom, jerry:jerry, acme:acme
On top of that, my own adm account as well, where I've done the same thing.

Until now I've seen no ill effects, but the devil's in the detail.