You experience everything for the first time. 
On Twitter, zoombombing, comparable to photobombing, has been a topic more and more often for the last few days. Zoombombing means that any troublemaker who disturbs zoom meetings by gaining unwanted access and disturbing the video conference with e.g. offensive chat messages. 
Very useful and clever by the way ;-)

I´m joining a very interesting initiative, the Cardiometabolism Virtual Seminar Series, every Friday at noon (EST). 
Last week, with > 150 participants, we were zoombombed, however the hosts managed the situation quite good and got rid of the trolls within minutes.
I guess, Lars Maegdefessel, who gave a highly interesting talk, did not even realize that there were some disturbancies. 

Zoom, BTW, has some measures avaiable, to avoid these zoombombings, like password protection and installing a so-called waiting room, where you can put the intruders as the host of the meeting.