Hiya, there are usually terms and conditions attached to every logo used by an organisation.
Branding represents a huge amount and is very often protected against use by individuals and other groups.
Intellectual property and
Trademarks / copyright.
Ofsted.gov.uk
Food Standards
NHS logo use is very specific and has it's own website -
NHSIdentity
Surestart brand page
HSE -
Health & Safety Executive's logo
Online linking - text and image ..
Every child matters and
DCSF
Direct.gov.uk
Recycling logo - article & unregulated
universal symbol use on wikipedia
Google's image search and copyright
Local partnership involving logos & promotional events / informational use can be fun to organise together ..
I have a few articles & press releases + competitions published onsite that use corporate logos. These are usually agreed beforehand and the content of the page checked by everyone involved before they are published / made public.
Hope this helps
xx