This must seem unimportant to many web developers, but for me it 's a major pet peeve. It's the web service that uses a blank user agent. Anyone who runs a blog receives huge amounts of scammers and scrapers trying to harvest information.
A lot of the poorly coded web scrapers fail to include a USER AGENT with their requests. Unfortunately there are still web services that retrieve web sites to digest the data for legitimate reasons that fail to include a USER AGENT. I drop them uniformly on the floor.
The most recent of my encounters with one ...