Many readers might be familiar with Virustotal. This service provides its users the ability to submit a file and have several anti-virus engines scan it. Unfortunately, several major anti-virus vendors decided this was not a good use of their product (probably because it exposes which vendors are lagging on getting updates out) and have badgered Virustotal to remove their engines. Apparently too many customers would come back to AV vendors using Virustotal results to harass them about lagging signatures.
Source: ISC.