I'd like to see some kind of stronger YC influence on ethics in the companies they fund. I realize that YC doesn't have any direct control over the companies, but it could be as simple as including good ethics in the traits they look for in startup founders.
A while back I started compiling a list of YC companies that spammed or otherwise behaved badly. It quickly got back-burnered by other projects, but there was AirBnB from W09, InstallMonetizer and SocialCam from W12, Zenefits from W13, Abacus and GetAirHelp from W14, Gradberry and OmniRef from W15 ... while so far it looks like the majority of YC startups are well-behaved, the trend was looking like there's a few in every batch that are willing to do shady things to meet their growth metrics.
Or, in Homejoy's case, maybe make a little more money while winding down.