This is what the customer has to say.
"Thank you for the suggestions for how I can prevent unauthorized personnel from attending my meetings. However, none of the suggestions are practical. My meeting is actually an all-day class that I'm teaching for a college. Students will be entering and leaving the class multiple times during the day, while I am doing my presentation (different topics are taught at different times of the day). There may be as many as 100 students. Therefore, I don't have time during the class to be monitoring who is in the "lobby" and then "admit" them into the meeting. Nor can I require each of them to have Webex accounts or the other similar administrative hurdles you mention. Nothing you suggest is a practical solution.
"I am requiring that students "register", but as soon as they register, and then I "accept" them (for example on Monday), they receive an invite email from Webex that allows them to enter the classroom (e.g. on Wednesday), but they might decide to share that invite email with 10 of their friends, all of whom can then enter the classroom on Wednesday without my knowing it.
"I am further frustrated by the fact that even though the registration process requires the user to enter first and last name, Webex makes NO use of that name when Webex shows me a list of "participants" who are logged on (e.g. on Wednesday). Instead, the Webex list of participants is whatever is the username of the computer which they are using to join up to the Webex meeting (I've proven this in experiments yesterday).
"What would be great is if a given email invite could be used by only 1 person at a time. That is, if a person shared their invite email with 10 other people, only one of those 11 people could be logged on at a given time.
"I don't understand why your company hasn't corrected this problem before now. This is a basic need for any teacher using your product to teach class remotely. In my case, the students all PAY to attend, and so any extra people (re-using an invite from a paying student) are getting the course FREE, and I won't know about it because I'm busy teaching the course all day long.
"This is EXTREMELY frustrating. Very disappointing."