In quantum physics.....?

That's the result of observation. Yep. It destroys the entanglement. Which is one reason why they claim entangled particles cannot be used to transmit info faster than light speed. It destroys the transmitter so to speak.

My rejoinder is that, hey...photons are cheap. So we stream them and so what if a transmitter is destroyed; there are more transmitters to come down the line.

And we don't care if they are up or down spin; it's the change in spin that counts as a signal. So, for example, if x is a change in spin (e.g., up to down or down to up) we could use a string of photons to send:

xxx xx xx xx xxx

Which is ... --- ... in Morse. That looks like info to me. Faster than light.

Of course we need to learn how to stream entangled photons. Ah well maybe next century.

Yes the entanglement stops once a measurement is made - it resolves the system into one of its states. You picked photons which have three angular momentum orientations. -1, 0, 1 (they are bosons). Let's look at electrons (fermions) which have spin up and spin down states (+1/2, -1/2) and denote the states as + and -. With entangled electrons the quantum state of the system can be (+, -) or (-,+) and this can be mathematically represented as

|Y> = 1/sqrt(2) { |->|+> - |+>|->| where the notation |+> means an electron in the spin up state and so on.

Now when you make a measurement on one electron, you are actually making it on |Y> the state of the system. So the measurement determines the state based on the single electron's spin. No need for information to travel faster than light - |Y> is either |->|+> or |+>|-> and you determine which state by measurement of one electron. Entanglement ensures the other electron has the opposite state. Again, no violation of the speed of light.