I've seen them throw out the recycling- I assume its if the trash truck comes first, they may assume the recycling truck isn't coming (since it usually comes first.) I don't think its a conspiracy, but I wish they'd just leave the recycling alone and I can put it back in the yard if they miss a pickup one week.

If I was sympathetic I'd chalk it up to poor training but I think its mostly that contractors don't give a rats ass as long as everything gets picked up. In Brookline the trash trucks are operated by the Town, so there is more incentive to do it right. In Somerville its contracted out and not all that monitored.