McCarthysm in cinema, and incredible plot elements
I can't believe the high score on this site. The movie is reasonably well made, and is entertaining to watch, but the whole premise is so juvenile. Those evil commies are so, so bad, that they make the criminals look good. I guess back then it would have been easy to tell the public that communists ate babies for breakfast.
Other posters have commented on how the gal falls in love so quickly and completely for a two-bit subway pickpocket. That's as much a fairy-tale as the depiction of commies as diabolic evil doers. Moe being a "well-known stoolie" is almost laughable; she would have been beaten up, or worse, by any pickpocket worth his salt.
The fact that Skip dressed better than the cops and knew how to use the public library and a microfilm reader was also a stretch, but that's the type of suspension of disbelief we viewers can put up with.
Overall, 5.5/10 would be a generous score for this cold war-era piece of propaganda.