Filters

Company cleans filters for reuse (Tulsa World)

3 Dec 2008

Big 4 Filtration scours industrial air filters and returns them to the owners, saving money.

Pupils can beat safe net filters (BBC News)

3 Dec 2008

Most children behave safely online but the filtering used in some schools can be bypassed by those up to no good.

Back door (BBC News)

3 Dec 2008

Some pupils can beat schools' net safety filters