Law firms love to talk about their pro bono exploits – until you ask them precisely what they do. At that point, many grow guarded and suspicious. That was what happened when Legal Week asked firms about their efforts in this area.

The more we investigated, the more it became clear that what is supposed to be a great example of human charity sometimes appears more like a marketing exercise that seeks constant praise but fears any basic scrutiny.

Legal Week's sister title The American Lawyer has been gathering pro bono data from law firms for years. It produces a highly influential annual league table that ranks the firms dedicating the most time to pro bono activities. We decided it would also be interesting to know which U.K. firms put the most effort into pro bono initiatives, so compiled a survey to find out. That's when the whole saga began.