Rebecca said:
For the record, taking a leaf from Google's book in this area has always been my preferred way of going about things. Also, to my knowledge, Google does not use the highest level of censorship as a default, but rather a moderate level (which is what I think we should be doing also).
Google's "moderate" filtering acts on images. Google's "strict" filtering acts on images text. Google (at least the site I am shown in the UK--other countries may vary) does not seem to have different levels of image filtering.