Thanks a lot! We use scrapy[1]. Our crawler's behavior is very polite so most of them won't block us. Easyjet for example is very strict against crawlers and will block most of them(and us).
It seems that easyJet has outsourced its anti-scraping protection to the company called "Distil Networks"[1].
I wonder how could they block screen scrapers using Chrome on Android with mobile IP addresses.