It is a long standing feature of any discussion on use of images in the classroom that Google Image searches should not be carried out in the classroom in front of children unless the teacher has checked that the results are not inappropriate. Examples such as Rabbit (not just the mammals), Prince Albert (not just Queen Victoria’s husband) and most girls names (having a naked on-line presence) have been discussed.
One aspect that is discussed less often though is the nature of copyright – it is not appropriate to use images in teaching materials that are not owned by you or licensed for your use. Fortunately more and more people are happy to share access to their materials though a ‘Creative Commons’ licence. One simple way of finding these is to use the ‘Anvanced Search’ option on Google Images and then select ‘Free to use or Share’ under the ‘Usage Rights’ category.