DOWNTOWN LOS ANGELES (KABC) -- Homeless advocates are suing the city of Los Angeles to stop authorities from seizing and destroying property that belongs to those living on the streets.Police conducted a sweep on Spring Street Tuesday to remove items from the sidewalk, marking them with police tape. The homeless people who live on the street say the items are their property."They want to get people who have a regular cart that they claim is stolen. They want to take you in for having a stolen cart and confiscate all your stuff," said a homeless man who wanted to be identified only as "Javier."It's all part of the city's effort to clean up the streets. However, critics say it is a violation of people's constitutional rights."The actual plan is the continuation of criminalization full scale and in some ways to double down to remove people from communities, to take property," said Pete White with the L.A. Community Action Network.Homeless rights activists held a news conference to announce a lawsuit against the city of Los Angeles. They say while the city, on one hand, claims it wants to fund programs to help the homeless, city agencies are coming out and seizing property and destroying it."This is the property that those individuals need to survive. These are their tents. These are their sleeping bags. These are their blankets. These are their medications, their documents," said Shayla Myers with the Legal Aid Foundation.Some are asking - at what point does private property become a public nuisance?City Councilmember Nury Martinez says she is getting complaints from residents who see homeless encampments in their neighborhoods."Communities in my district also are asking for some relief in terms of what do we do with encampments that are as big as 300 people, and what do you do with people who refuse help?" Martinez said.The city attorney's office will have to deal with all the legal issues in this lawsuit. The office did not have an immediate comment following the announcement of the lawsuit.