SAN FRANCISCO (KPIX 5) – Anti-abortion activists, armed with chalk, scribbled slogans of protest outside the home of a San Francisco Planning commissioner.

The unusual political protest was caught on camera. Pro-life activists can be seen hopping out of a van and scrawling messages on the street.

The messages were targeted at a San Francisco Planning commissioner.

San Francisco Mayor Ed Lee said, “You know that’s a form of free speech – I’m going to leave it up to our police department.”

And on Wednesday, police were out investigating the surprise action that was both well-timed and well-executed.

Four vans pulled up, blocking off both ends of the street and about two dozen teenagers pop out, quickly chalking messages like: ‘Stop Planned Parenthood,’ ‘Stop Killing Babies,’ ‘Life Is A Gift’ and ‘Richard Kills.’

They were referring to the target of the attack, Planning Commissioner Dennis Richards.

Richards said, “I can differ with you on opinions, but you don’t have to come and terrorize my neighborhood about it – I think that steps over the line.”

At issue was a recent vote by the Planning Commission in favor of Planned Parenthood building a new flagship location on Bush Street.

The irony is that Richards wasn’t even there.

“I was out of town,” he said.

For Richards’ neighbors, the surprise attack was a jolt.

Neighbor Paige Grey said she saw, “…people writing chalk on the sidewalk in front of our houses, on the street.”

And when Grey stepped out to confront one of the activists writing ‘Dennis Richards Kills Babies’ on her sidewalk, Grey said, “She got in my face about her First Amendment rights.”

Then, just as quickly as it began, it was over.

Grey said, “The main guy said ‘in the vans, let’s go’ and it was over and they were gone. And he did say ‘good bye’ and ‘have a nice day.'”

Richards said, “What really pissed me off was one, they had kids – maybe 10, 12, 15 years old coming and doing this.”

Richards said, “The other thing that really upset me was the fact that there were gay slurs.”

But Terrisa Bukovinac with the pro-life group, The Future of San Francisco, defended the action.

“No crime was committed. They’re kids, they’re activists. They have to be creative especially in a place like San Francisco

Bukovinac said, “I am supportive of that type of activism. I don’t see anything wrong with it.”

And the gay slurs?

Bukovinac said, “The only thing that was mentioned was someone said ‘your car is gay’ and these are kids and they say inappropriate things.”

Richards said, “They didn’t break any laws I understand, but I mean the thing for me is this could escalate.”

Mayor Lee said, “i guess this is their right, I just hope that these kids are also being taught about compassion, support and embracing of different values, as well as their point of view.”

Three other commissioners’ homes may also have been targeted by the same group.

There’s also a good chance the groups are going to try to appeal the Planning Commission’s decision.