>> I'm Dropstitch Murphy,
and this is my Wisconsin Life.
? ?
[dramatic music]
>> This is Ms. Murphy.
That's not her real name,
and this...
>> [deep voice]: It started
when my daughter was a baby.
? [music crescendo] ?
>> Is not her real voice.
She's asked us
to hide her identity.
See, Ms. Murphy has a hobby,
something that has to be done
in secret,
often in the dead of night.
? ?
[ominous music]
>> Nobody sees you.
Nobody knows who's doing it.
That's kind of how it's done.
>> Through that stealth,
this obsession is spreading.
>> It's all over.
I think some areas,
it's happening more.
On the coasts, England seems
to have some over there.
>> But Ms. Murphy
doesn't ply her trade
on the coasts or overseas.
She works in La Crosse.
She
is a yarn bomber.
[audio "whoosh" sound effect
and videotape rewinding]
>> She is a yarn bomber.
? ?
[upbeat techno music]
The idea of yarn bombing
is simple.
It's like temporary graffiti.
But instead of painting
on an object,
artists knit around it.
>> I'd seen it in some magazines
and then started seeing it
a little bit on the Internet.
And then, this book called
"Yarn Bombing" came out.
I talked to some friends
and said we should do this.
>> During the past few years,
Murphy and a few friends have
yarn bombed around La Crosse.
They call themselves
the Bluff-Side Bombers.
She calls herself
"Dropstitch Murphy"
after a Celtic punk band.
Their goal?
>> Just for fun, I think,
and get people to smile.
? ?
>> Lately, they've started
working out in the open.
They've eased up
some of their disguises.
When it comes to Ms. Murphy's
voice, so can we.
>> [normal voice]: I prefer
putting it places
where I have permission,
and I can do it in the daylight,
and I can see people smile
when they walk by, I guess.
It's less stressful.
Mostly, I do bike racks.
I've done some stuff on trees.
You have to use math.
Measure the circumference.
Figure out how many stitches
you get for that.
And then however long
you want to make it.
For me, that's the easy part.
Sewing up is no fun.
>> While Dropstitch Murphy
works with other yarn bombers
in Wisconsin,
she's also become part of
a global community.
>> I actually sent a piece
to New Zealand
for a big project there during
the Rugby World Championships,
or something.
People from around the world
sent pieces in.
>> Despite those
global connections,
the greatest rewards
often come closer to home.
>> The last one I put up
at the library, lots of people
would stop and say
that they really liked it.
They thought it brightened up
the neighborhood.
I get positive reaction.
Online, you get lots
of negative.
But when people walk by
and see it, very positive.
Little kids especially.
? ?
>> So for all that sneaking