I think any large group of people - marching, chanting, shouting, or whatever - can be a bit disconcerting, especially in confined spaces. The thing about London, as with other major cities, is that it has always been a prime location for terrorist attacks. I am not afraid in London when there are marches, but I do feel somehow less confident pushing my way through marchers to get past. Occasionally when the alarm went off in a tube station, or when the bomb curtain was dropped at Westfield, or when a knife was thrown on the platform from a bridge in Leyton, I would gulp and freeze for a second. But I don't remember that at that moment I instantly associated the danger with Islam, although sadly a lot of the attacks turned out indeed to be related to that cause. I guess it's difficult to separate the two in my mind.