Google Discussion Groups - password demanded

[Martin963]

I look from time to time at such google discussion fora as

groups.google.com/group/fr.rec.tv.terrestre/

but more recently Firefox occasionally demands that I submit my Google account password - yes I do have one somewhere but I can't be **sed to go and look for it.

So in order to access these discussion pages I have to use Google Chrome (oh the irony) rather than Firefox to look at the web page, presumably because I've never used Chrome to access my Google account.   At least that is what I'm guessing is happening.

Now I'm all for a bit of security where it matters,     but as I've never contributed to the discussion forum in question (therefore I'm not a member),   merely looked at it,   I'm at a loss to know what's so damned important about it that it needs me to identify myself. 

Can anyone shed light on this?   Is this what Google were banging on about a couple of months ago with their revised Terms and Conditions?