I'd say the usage of 'view their photostream' is correct.

when did it become standard English? I know that it has slipped into common usage, but I fear that all my English teachers would disagree.

en.wikipedia.org/wiki/Si... "debate continues about its usage"

and in the case I cited, the gender was known.

wellllll ok

all my professors were good my usage of it, so there you go!

"their". "his" and "hers" are awful, english teachers be damned.

and it pressures websites to prompt for gender, which is dumb.

let's move the language forward!

here here for their their!

meh