return a random subset of a given stream

RandomSubset.java

import java.util.List;
import java.util.Random;
import java.util.stream.Collectors;
import java.util.stream.Stream;

import java.util.Arrays;

public class RandomSubset {
    // Returns a random subset of a given stream.
    static <E> List<E> getRandomSubset(Stream<E> stream) {
        Random rand = new Random();

        return stream
            .filter(o -> { return rand.nextBoolean(); })
            .collect(Collectors.toList());
    }

    public static void main(String[] args) {
        if (args.length == 0) {
            System.err.println("Usage: java RandomSubset StringElement [StringElement]+");
            System.exit(1);
        }

        Stream<String> stream = Arrays.stream(args);
        List<String> result = getRandomSubset(stream);

        String output = String.join(" ", result);
        System.out.println(output);
    }
}