Not knowing how they are connecting one of the below should give you
the information for currently connected users.
connected by ssh’ing into the asa box and enter:
show vpn-sessiondb summary ( tells what type of connects are current active
show vpn-sessiondb svc (show SSL VPN Clients)
show vpn-sessiondb remote ( IPsec Remote Access sessions
show vpn-sessiondb webvpn (webvpn connections
show vpn-sessiondb l2l (IPSEC lan-to-lan connections
Test it out by connection yourself as that user does and run the above to see which one you need.
You can also setup logging and pull “ASA-3-716001″ for webvpn connections.