Its not an assumption. The same Internet I have here at my house is the same Internet those in the British Isles have. They, just like me, have the ability to find out about such things if they are so interested. If they aren't interested then that is their fault/problem, not mine. I like seminars, especially those concerning biblical topics, as such I look for them on the Internet - everyone has this same ablilty. I guess that maybe some may only see the Internet as a way of chatting with friends - but it is so much more.
As I stated earlier, I didn't find out about that seminar via local promotions or from my church - I found it on the Internet first. There is no valid reason in the world why those who have such access to information can miss something like this unless they simply weren't looking.