A New York judge ruled Monday that the thousands of signatures gathered by Robert F. Kennedy Jr.'s campaign in the state were "invalidated" after a Democrat-aligned group argued he misled voters by listing as his home an address he rarely visits.

The judge, Christina Ryba, ordered the New York Board of Elections to not include Kennedy's name on the ballot this fall.

A lawyer representing Kennedy told reporters last week they would appeal any ruling that went against them.

The ruling could prompt Democrats to bring similar lawsuits against Kennedy in other states where he gathered signatures from registered voters to appear on the ballot.

-ABC News' Will McDuffie

The FBI is investigating alleged attempts by Iran to target the then-Biden-Harris campaign, sources familiar with the matter confirmed to ABC News.

The alleged targeting via spear-fishing emails occurred before Biden announced he would exit the 2024 presidential race, the sources said.

While the campaign was targeted, the alleged hack was not successful, sources added.

The FBI is investigating a purported hack of the Trump campaign, according to a brief statement from the agency earlier Monday.

The FBI did not attribute the hack to anyone in its statement.

A source familiar with the matter told ABC News that Trump adviser Roger Stone has also been informed that his email accounts have been compromised, and that he's cooperating with any investigation into the matter.

The Washington Post first reported the news.

-ABC News' Luke Barr, Gabriella Abdul-Hakim, Will Steakin and Katherine Faulders

President Joe Biden, former President Barack Obama, and Bill and Hillary Clinton are all tentatively slated to speak at the Democratic National Convention next week, sources familiar said.

The working speaking schedule, which can always change, is as follows, according to the sources:

Monday: President Joe Biden, former Secretary of State Hillary Clinton
Tuesday: Former President Barack Obama
Wednesday: Vice presidential nominee Tim Walz, former President Bill Clinton
Thursday: Vice President Kamala Harris

-ABC News' MaryAlice Parks and Fritz Farrow

Trump posted on X for the first time in nearly a year ahead of his conversation with Elon Musk scheduled for Monday night.

The video posted is a previously released campaign ad referencing his multiple indictments and telling supporters, "They are not coming after me, they are coming after you."

The last time Trump posted on X was Aug. 24, 2023. It was a picture of his mugshot from Fulton County, when he turned himself in to authorities following his election interference indictment in Georgia.

-ABC News' Lalee Ibssa, Kelsey Walsh, Soorin Kim