Re: He should have just emailed it to himself encypted of course
Data caps in the western world are not an issue.
They may not be an issue for you personally. They are an issue for a lot of others - with many countries and operators, both fixed and mobile, your "unlimited" data plans get throttled once you reach a certain data volume [e.g. my cable data gets throttled past 2TB/month; my wireless data gets throttled past 50 Mb/month (I am too cheap to pay more than EUR 5 for a data plan)]. Furthermore, in many western countries, "unlimited" wireless plans cost a a lot more than 30 quid a month, if they are available at all - take a look at the wireless data pricing in the US or (shudder) Canada.
In most of the world (western or otherwise - I travel a fair bit, and I do not see much of a difference between western countries and places like China, Thailand, or Russia in terms of the wireless internet infrastructure), it is usually not a problem transferring a few gigabytes from your base. If that's all you need - fantastic, and congratulations. If you need more data, carrying it with you is frequenty the only practical alternative.