by Oliver Obermayr.
... go to Site Administration > Users > Permissions > Define Roles, then double click your web services role,...
@Chris C, just wanted to clarify, what do you mean by "web services role", because I can't find this thing in my Moodle (v.2.4) in Site Administration > Users > Permissions > Define Roles. If you mean list of roles, then I have there Student Role, and I already allowed moodle/user:viewdetails by editing named role. But result is wihtout any affect. Could you help me with this? Thank you