I've never understood why companies do this. Twitter opened a small office in London and never said where it was.
London is massive, and there are certain areas that tech/digital people want to work in. Covent Garden - probably yes. Shoreditch - yes. I think Twitter ended up somewhere near Blackfriars which is just full of legal suit drones.
If you're opening an office in London, and you've done your research, you need to PR the hell out of the location!
I thought twitter basically ended up moving international head office to Ireland not London so the London office is tiny. Facebook wants developers so has to be a bit more visible, while Twitter was just a sales office. Guessing Facebook will do events there soon.
As for the article, it is just not very thorough. See this comment for location and link to article about it. Its a high budget office. http://news.ycombinator.com/item?id=4289895
Twitter definitely have an engineering presence in London, because I've been hit up for Android referrals by their recruiters. I have a feeling Twitter's London based engineering team is a result of the TweetDeck acquisition.
Re: Blackfriars - it's not a totally nuts location for a mobile engineering team, because it's where Symbian's offices are/were. Lot of mobile engineering talent already commuting to the area.
"A stones throw from Seven Dials", having moved out from Carnaby Street. Its a 36,000sq ft listed building, probably fairly easy to work out which one by looking I would guess. Near Mozilla's new office and Yahoo! but sufficiently far from Google...
