While this Wisconsin statutes allow law enforcement officers to "demand" ID, there is no statutory requirement to provide them ID nor is there a penalty for refusing to, hence Wisconsin is not a must ID state.
So in Wisconsin, how can you tell if an officer asking you to identify yourself has reasonable suspicion? Remember, police need reasonable suspicion to detain you. So one way to tell if they have reasonable suspicion is to determine if you’re free to go. You can do this by saying “Excuse me officer. Are you detaining me, or am I free to go?” If the officer says you’re free to go, leave immediately and don’t answer any more questions. Walk but do not run away from the the police since running can give the police reasonable suspicion to detain you.
If you’re detained, you’ll have to decide if withholding your identity is worth the possibility of arrest or a prolonged detention. In cases of mistaken identity, revealing who you are might help to resolve the situation quickly. On the other hand, if you’re on probation or parole, for example, revealing your identity will likely lead to a legal search.
Remember that the officer’s decision to detain you will not always hold up in court. Reasonable suspicion is a vague legal standard, and police often make mistakes. So if you’re searched or arrested following an officer’s ID request, you may contact an attorney to discuss the incident and explore your legal options.
By contrast, in Hiibel v. Sixth Judicial District Court of Nevada, 542 U.S. 177, 181 (2004), a Nevada statute (Nev. Rev. Stat. § 171.123 (2003)) specifically required that a person subjected to a Terry stop “shall identify himself.” The Supreme Court held that the statute was constitutional.
Of course, the police believe they have an absolute right (just where in the Constitution the police were granted any rights I am not sure) to demand identification of a citizen. Jeff Bray, Senior Legal Advisor, Plano, Texas, Police Department, “Suspects Who Refuse to Identify Themselves,” The Police Chief: The Professional Voice of Law Enforcement vol. 74, no. 4, April 2007, http://www.policechiefmagazine.org/magazine/index.cfm?fuseaction=display_arch&article_id=1150&issue_id=42007. In Milwaukee, Police Chief Flynn created a legal fiction by saying his officers are entitled to “legal pretext stops.” Don Walker, “Chief Flynn says police will adjust tactics to battle violent crime,” Milwaukee Journal, January 11, 2013, http://www.jsonline.com/news/milwaukee/chief-flynn-said-police-will-adjust-tactics-to-battle-violent-crime-4i8boc3-186537711.html. With all due respect to Chief Flynn, there are no such constitutional animals as “legal pretext stops.” If a stop is pretextual, it is unconstitutional. A police officer simply cannot seize and search every person whom he sees on the street or of whom he makes inquires. Sibron v. New York, 392 U.S. 40, 64(1968). “Before [a police officer] places a hand on the person of a citizen in search of anything, he must have constitutionally adequate, reasonable grounds for doing so.” Id.
The National Lawyers Guild and the ACLU of Northern California, recommend to either remain silent or to identify oneself whether or not a jurisdiction has a "stop and identify" law:
And in any state, police do not always follow the law, and refusing to give your name may make them suspicious and lead to your arrest, so use your judgment. If you fear that your name may be incriminating, you can claim the right to remain silent, and if you are arrested, this may help you later. Giving a false name could be a crime. "Know Your Rights! What to Do if Questioned by Police, FBI, Customs Agents or Immigration Officers". National Lawyers Guild, S.F. Bay Area Chapter; ACLU of Northern California; American Arab Anti-Discrimination Committee.
In a more recent pamphlet, the ACLU of Northern California elaborated on this further, recommending that a person detained by police should:
. . . give your name and the information on your drivers’ license. If you don’t, you may be arrested, even though the arrest may be illegal. "Your Rights and the Police". ACLU of Northern California.