"The vacants are a huge, key issue," says Adam Van Bavel, a community activist from Pigtown, one of Baltimore's better-known transitional neighborhoods.

When Van Bavel moved to his block in Pigtown in 2007, only five of the 25 houses were occupied. Drug dealers used the vacants on either side of him. Now, most houses are occupied — including four vacants in the last year taken over by homeowners.

"Pigtown is one of those neighborhoods that could have easily been a Canton or a Federal Hill 10 years ago, but for some reason it wasn't," he says. "I can tell you that the residents of the neighborhood are doing everything we can to get more people moving into Baltimore City."

Since 2008, only 14 of Baltimore's more than 225 neighborhoods have sold more houses each year than the previous year. One of those is Union Square. That puts the tiny South Baltimore neighborhood with its $61,000 median home sale price in 2010 in the same category as Federal Hill ($285,000 median home sale in 2010) and Butcher's Hill ($250,000 median home sale).

For a neighborhood to consistently attract more residents, it needs to offer safety, cleanliness and a sense of community. And to build such a community, neighborhoods often need a leader.

Rosemary Wakeman, director of the Urban Studies Program at Fordham University, said younger, more daring people are often the first to start a wave of revitalization in a neighborhood.

"Often, the artist community makes up the pioneers," she said. "I think individuals can make a difference when they act as a functioning community. You have to have community leadership that can lobby for better services in a sustained way over time."

It's by no means an easy task for those who take on the challenge. Such urban pioneers often risk their time, money and safety in such an endeavor.

Taylor recently finished his fifth year as president of the Union Square Community Association and challenged for a City Council seat but lost. Sometimes, he thinks there might be something wrong with him for even undertaking such a mission in the first place.

"I don't know if we should be lauded or put in an insane asylum," he says.

Just ask Sebastian Sassi, who worked for years to try to remake Pigtown before deciding to move out. A hot neighborhood for investors a few years ago when it began a transformational period, Pigtown's home sales have regressed recently.

But few fought as daringly as Sassi during that time. Sassi created a website, Pigtown John Watch, to try to embarrass the johns and prostitutes into leaving. He got a right-to-carry permit and began to walk the streets with another resident, Nathan Flynn, doing patrols.

That was until someone shot what appeared to be a bullet through the window of Flynn's car, and Flynn later decided to move.

Finally, earlier this year, after his wife had a baby, Sassi joined him in getting out of Pigtown.

"It just didn't seem a worthy risk to my child to have me keep living there," he writes in an email.

"Baltimore has made it clear they don't value taxpaying families and our safety," he says. "They're trying to save places that are beyond saving and in the process losing places that can be saved."

Van Bavel, who's still bullish on the neighborhood, doesn't blame the police, but does think the city and the court system could do more.

He gets upset when he sees trash collectors leaving cans strewn through the neighborhood. He worries about repeat offenders who are let out on the streets.

"We've got the community and the police department working. The city and the legal system aren't," says Van Bavel, who is running a write-in campaign for City Council. "These people go in there and it's just release, release, release. That's why you're seeing middle class flight."

Operation smackdown