Why Are the Toronto Police Assaulting Journalists?

From the Twitter of Steve Paikin

i was "escorted" away by police so couldn't see how many arrested, but it must have been dozens.
half a minute ago via web

literally more than 100 officers with guns pointing at the crowd. rubber bullets and smoke bombs ready to be fired. rubber bullets fired
1 minute ago via web

so the police just started arresting people. i stress, this was a peaceful, middle class, diverse crowd. no anarchists
3 minutes ago via web

police on one side screamed at the crowd to leave one way. then police on the other side said leave the other way. there was no way out.
4 minutes ago via web

the demonstration on the esplanade was peaceful. it was like an old sit in. no one was aggressive. and yet riot squad officers moved in.
5 minutes ago via web

i can appreciate that the police were on edge today, after seeing four or five of their cruisers burned. but why such overreaction tonight?
6 minutes ago via web

the officer who escorted me away from the demo said, "yeah, that shouldn't have happened." he is correct. there was no cause for it.
7 minutes ago via web

no cameras recorded the assault. and it was an assault.
7 minutes ago via web

a third punched him in the stomach. totally unnecessary. the man collapsed. then the third officer drove his elbow into the man's back.
8 minutes ago via web

the journalist identified himself as working for "the guardian." he talked too much and pissed the police off. two officers held him....
8 minutes ago via web

they repeated they would arrest me if i didn't leave. as i was escorted away from the demonstration, i saw two officers hold a journalist.
9 minutes ago via web

i saw police brutality tonight. it was unnecessary. they asked me to leave the site or they would arrest me. i told them i was dong my job.
10 minutes ago via web

have left the demonstration on the esplanade. have got to a computer. here come a lot of tweets about what i saw.
11 minutes ago via web

i. gone police escor me away
about 1 hour ago via mobile web

weapons are rubber bulles
about 1 hour ago via mobile web

mny arress now. inexplicable ppl say "we wan o go home cops overwhelming crowd
about 1 hour ago via mobile web

Steve Paikin is one of the best-known, most respected journalists in Canada. He moderated their last federal leadership election debate. He has no axe to grind, no ideological agenda; and he is exactly the wrong person to piss off.

So why the hell did the police come within a hairsbreadth of beating the holy hell out of him? And verifiably assault a journalist from the Guardian? Yes, there was violence against property earlier today. Compared to what could have happened, it was almost orderly. But as I said, police overreaction WILL CAUSE ESCALATION.

Up until now, they hadn't. Even the tear gas incident was relatively minor compared to what COULD have happened. They were showing restraint. And now this.

I'm not looking forward to tomorrow.