EFF fought for transparent elections, forcing e-voting companies to comply with North Carolina state law. In November 2005, Diebold Election Systems filed suit against the North Carolina Board of Elections to avoid a law requiring vendors to place their machines' source code into escrow. EFF intervened in the case, getting the complaint dismissed, and Diebold subsequently withdrew its e-voting machines from North Carolina elections.

EFF defended the use of voter-verifiable paper trails in Florida. The National Federation of the Blind filed suit to force Volusia County, Florida to spend approximately $700,000 of state funds on Diebold voting equipment that the county had repeatedly rejected. EFF and a Florida attorney filed an emergency friend-of-the-court brief in the case on behalf of disabled residents who opposed the purchase. A federal District Court judge ruled in favor of the county, giving it the opportunity to purchase voting equipment that is both accessible to disabled voters and that creates an auditable paper trail to protect against errors and fraud.

EFF and the ACLU of Northern California filed suit in federal court on January 14, 2009 to protect the privacy and free speech rights of two San Francisco Bay Area community organizations after the groups' computers were seized and the data copied by federal and local law enforcement.

The 11th U.S. Circuit Court of Appeals found a Florida man’s constitutional rights were violated when he was imprisoned for refusing to decrypt data on several devices.  This was the first time an appellate court has ruled the 5th Amendment protects forced decryption – a major victory for constitutional rights in the digital age.  EFF filed an amicus brief in this case.

In 2012, EFF used CDA 230 to end a legal threat to a lawyer ratings web site (LawyerRatingz.com) for postings by third parties. EFF filed a declaratory relief lawsuit which resulted in a covenant not to sue by a small Florida probate law firm – the Law Offices of Adrian Philip Thomas, P.A.

In March 2010, EFF filed an amicus brief urging the Illinois Court of Appeals to protect the identity of an anonymous critic who upset a local politician. Our brief set forth the appropriate First Amendment standard that should be applied to protect the online critic’s identity from curious or vituperative opponents. In November, the Court of Appeals overturned the trial court’s order and protected the identity of the anonymous speaker in question, adopting much of the substance of our First Amendment argument.

EFF filed an amicus brief in this case in support of a man who was indicted under the a federal anti-stalking statute for repeatedly tweeting caustic criticisms of a public figure, a Buddhist sect leader who herself made extensive use of social media. In December, 2011, the judge agreed with EFF and dismissed the case, ruling that "the First Amendment protects speech even when the subject or manner of expression is uncomfortable and challenges conventional religious beliefs, political attitudes or standards of good taste."

In February 2008, Swiss bank Julius Baer filed suit in federal district court against Wikileaks for hosting 14 allegedly leaked documents regarding personal banking transactions of Julius Baer customers. The court subsequently issued a permanent injunction disabling the wikileaks.org domain name and preventing that domain name from being transferred to any other registrar. EFF, the ACLU and the ACLU of Northern California moved to intervene in the lawsuit, joining other amici, arguing that the unwarranted injunction violated the First Amendment as an unlawful prior restraint. The court agreed with our arguments, dissolving the injunction and allowing the wikileaks.org domain name to go back up. Julius Baer subsequently moved to dismiss it case.

In January 2012, the U.S. Supreme Court unanimously confirmed that Americans have constitutional protections against GPS surveillance by law enforcement, holding that GPS tracking is a "search" under the Fourth Amendment.