From the NYT:
The immigration authorities planned to continue making arrests throughout the week. They identified at least 2,000 targets of the operation, but may ultimately arrest far fewer. In most such operations in the past, only 20 to 30 percent of the targets have been apprehended.

Because agents cannot legally use force to enter the homes of their targets, they rely on the element of surprise to be successful, suggesting that the current, highly publicized operation could yield an even smaller proportion of arrests.
Back in the 70's I was running a plant (my first one) in Linden NJ--just outside NYC. By far, the majority of the work force were from Columbia and although this was long before E Verify I have to believe most were here illegally.

They had an underground that was amazingly active--and accurate. If they got wind of ICE activity in the area they didn't show up---it shut the plant down!

Because of that experience I had watched the current dog and pony show from the WH with "expectations"----and nope---I wasn't disappointed.

I do not support illegal immigration---but this is almost comical