[marcinzm]

It's not a question of the user knowing the value, it's a question of the chop shop the thief sells the bike to knowing.

[tempestn]

A lot of bike thieves steal bikes to use themselves or to sell as bikes. Nothing will prevent every potential theft, but I can see how it would help.

[usrusr]

But the "use for themselves" thief is deterred with even the cheapest U lock (even with a moderately strong cable) as long as it's not trivially pickable.