I'm tired of seeing lurking and scumtelling get intrinsically tied together.
Reality is that lurking is arguably the worst maf strategy. Why? Because lurkers are automatically singled out and suspected on principle. Therefore, in many situations mafia have every reason to not lurk. Mafia often just want to blend in, and the easiest way to blend in is by being perceived as a "contributor."
There are a lot of good, town-driven reasons to lurk. Sometimes I'm just trying to read two ccs and a guiltied person argue with each other to get reads. Sometimes I genuinely have nothing to say at the moment. Instead of polluting the waters with FOSes that I pulled out of my butt and random filler lines, I'd rather see what other people might have to say that is meaningful and then gain direction from there. Sometimes I'm a bored blue in a large setup and I just want to see how the dominoes fall on d1 without my bias.
Now obviously, some who says two sentences through three days is being incredibly anti-town. That's an extreme level of lurking that goes above and beyond. And sometimes mafia DOES just want to lurk so as to avoid slips or scumtells. This is 100% true. But mafia also sometimes ccs or doesn't, sometimes claims early or late, sometimes bandwagons or doesn't, sometimes busses or blitzes. A lurker could very well be mafia, but instead of creating a false equivalence of "lurking = mafia" because someone didn't speak much on D1, try to figure out why the person might be lurking. Ask the person. Then weigh his/her response against all the other evidence to make a decision. Just as you would in any other situation.