Why EchoLink links licensed amateurs over the internet, so the system must verify you are actually licensed before it lets you connect. Registration involves submitting your call sign and documentation proving you hold a valid amateur license, after which your account is validated. This keeps unlicensed users off the network, since EchoLink nodes can key up real transmitters on the air.
Watch out The choice requiring a General class license is wrong because any licensed amateur, including a Technician, may use EchoLink; the software itself is free, so no purchase is needed.
EchoLink is free but not anonymous: prove your license, register your call.