Anti-Kettling techniques

I have been looking at the recent demonstrations in the UK over tuition fees and was wondering why the demonstrators don't split up in to many different groups as soon as they see police congregating instead of waiting to be kettled when it is too late to do anything, or why not plan marches to have multiple groups?

>>11
I don't know what country you're from but around here the students are much more politically mature than the rest of society. They are also much better informed.