Hey!
Vielleicht kann sich jemand von den Englisch Profis mal meine Übung zum Partizip ansehen & nachgucken, ob alles richtig ist.
People watching (People who are watching) a demonstration often do not realize what it takes to organize such an event.
I talked to Kyle T., an animal rights activist. Because regularly organising (Because he regularly organises) demos against factory farming, ...
After having planned (After you have planned) your demo, the next thing is to tell the local police.
When having been informed (When they have been informed), they can plan how they are going to deal with it.
You should also give clear instructions to all the people attending (people who are attending).
For example, people demonstrating (people who are demonstrating) for the rights of farm animals shouldn't carry posters against child labour.
However, the most important thing is that everybody involved (everybody who is involved) should act peacefully.
If feeling (If they feel) positive about the demonstrators, people are more likely to support the case!