Seriously, freedom of speech/religion is all fine and good until you get confrontational about it.
Even confrontation is fine, if it is handled in a civilised fashion. Limiting expression is bad, regardless of what you think of the ideas. However, the method of expression is important. The problem arises when it becomes bothersome, inflammatory, or is at risk for inciting a crime. Don't know about the UK, but even here in the US, you can't hold demonstrations or street preach without permits, you can't incite riots, you can't incite violence.
Now I don't know the exact circumstance of the case, it does seem to be allot of accounts without evidence, and so far I have only seen one source for the accounts, which is why I am not willing to say whether this particular charge is warranted or not.
However, I do feel that people generally have the right not to be hassled when going about their day. The street corner is not your church. Passersby have not asked for your opinion, nor expressed any interest in your religion. If you have a permit, permission from the businesses, and no one complains, fine. But the minute you start making people uncomfortable you have crossed the line into harassment. This is the very essence of the crime of disturbing the peace.