Stockton, California Mayor Anthony R. Silva attended a recent mayor's conference in China, but his return trip took a bit longer than usual. At the San Francisco International Airport (SFO) this week, agents with the Department of Homeland Security detained Silva and confiscated his personal cell phone among other electronics. According to comments from the mayor, that may not even be the most alarming part.

“Unfortunately, they were not willing or able to produce a search warrant or any court documents suggesting they had a legal right to take my property," Silva told SFGate. "In addition, they were persistent about requiring my passwords for all devices.”

The mayor's attorney, Mark Reichel, told SFGate that Silva was not allowed to leave the airport without forfeiting his passwords. Reichel was not present for Silva's interaction with the DHS agents, either. The mayor was told he had “no right for a lawyer to be present” and that being a US citizen did not “entitle me to rights that I probably thought,” according to the paper.

As of Friday, Silva had not yet received his property from the SFO detention. SFGate reports Reichel contacted the US Attorney’s Office in Sacramento, but they would not comment on whether they still had the mayor's possessions. The paper also reached out to a spokesperson at US Immigration and Customs Enforcement, but that office also refused comment. (Ars has reached out to the mayor's office for any new information, and we'll update this story accordingly if we hear back.)

Authorities demanding access to password-protected devices has become a hot-button issue across the country, highlighted in particular by the federal government's ongoing battle with Silicon Valley over the lack of crypto backdoors in modern smartphones. At the end of last month, one US District Judge in Pennsylvania ruled that forcing suspects to surrender their passwords was unconstitutional on Fifth Amendment grounds.

Evidently, Silva was well aware of the situation and only had his concerns heightened by first-hand experience. Talking to SFGate, he briefly compared the government battle on privacy to notorious dictatorships worldwide.

“I think the American people should be extremely concerned about their personal rights and privacy,” Silva told the paper. “As I was being searched at the airport, there was a Latino couple to my left, and an Asian couple to my right also being aggressively searched. I briefly had to remind myself that this was not North Korea or Nazi Germany. This is the land of the Free.”

Update, 10/5: As noted by some commenters, the local Stockton newspaper (The Record) talked with two anonymous law enforcement sources that said the Silver detention may be linked to an ongoing probe. Neither the anonymous sources, the mayor, nor the paper mention what that probe might be. Within The Record's recent archive, the biggest incident involving Silva appears to be an alleged intoxicated tussle within a limousine from late 2014.

Silva also released a statement last week on the situation. The mayor's office still has not responded to a request for comment from Ars Technica.