I also wonder why more mob guys don't invest heavily in anti-surveillance and counter-surveillance. Just like there's very small bugs nowadays, there's also very advanced anti-surveillence devices to help them find bugs, recording devices, wires, etc.
Counter-surveillance is more tricky as they would have to track the FBI vans and it's pretty difficult to outsmart the feds in their own game, but it can be done.

My guess is they haven't got the means to get the latest devices? They obviously have the money and some of the bosses have the brains. I know for a fact cartels use these devices, along with opposing political parties in other 2nd and 3rd world countries.