After a spate of articles [NYT] noting the uptick in Britishisms in the US, Lynne Murphy offers a word of caution about swearing:
Americans are notorious for using and not understanding its connotations of wanker (see the comments in that post for some stories). Americans imported wanker without necessarily knowing wank (to masturbate), and so it sounds like a fun, silly thing to call people. But calling someone a wanker is less like calling them a jerk, and more like calling them a jerk-off. In the other direction, we've noticed British students coming back from a year abroad in the US and using the youthy use of douche as an insult in social contexts in which my brothers/nephew would avoid it in the US (the family dinner table, with grandma. OK, ok, I'm talking about my brother-in-law).
Newcastle Brown Ale's No Bollocks ad campaign is specific to America and it's not clear that such a campaign would be allowed in mass media in the UK. The Advertising Standards Authority's 'Deleting Expletives' report of 2000 put bollocks as the 8th most offensive word according to the British public. (Wanker was 4th, before nigger or bastard.) Words lower in the 'severity of offence' list than bollocks include arsehole, twat and shit.
The Dish 