[Y0L0]

Using your DSLR as a Webcam is a great way to destroy the sensor.

[bjcy]

I'm interested in knowing why this is the case. Can you point me to any resources with the technical reason why this happens?

[bluetidepro]

I second this. Doing this has ruined my friends DSLR. Not sure the technical reasons behind this, but it does indeed have consequencing effects.

[zacksjoden]

I've read about this a bit for mods on DSLRs for taking older Canon's and allowing them to record video. If the DSLR isn't designed for recording video the sensor isn't designed for continuous light exposure which will heat up an ruin the sensor. I don't know the differences but I'd imagine using one of the newer DSLRs that have video recording capability as a webcam would be fine.