They were not after Anderson at all
Andderson had the horrid luck of asking people to help him who had agents taping THEM already! How is that for bad timing?
There was secret surveillance going on a lot of other people already. When Anderson shows up at Ingrid's apt, they have already been taping her for who knows what reason, prob one of her clients.
When Anderson was meeting with Angelo, tapers said they didn't even care about Anderson, all they cared about was Angelo.
Obviously, they are not happy when they realize they have taped a burglary and all their illegal wiretaps will now be discovered and ANYTHING they have taped on other criminals will not be allowed in court.
Once I saw the IRS was doing it, I knew they were NoT after Anderson.
I am sure that once Anderson was either convicted or let go, they went back to their secret taping.
Get it?