We have already said that this can be very effective and there are a few options available to Joomla sites and component developers.
For example SH404 integrates Project Honey Pot, Akeeba Admin Tools implements Bad Behavior etc.
It has always struck us as strange that a lot of components all seem to implement the same tools in their products so that a site with many components from different suppliers ends up configuring the same technique over and over again. Surely it is better to have the protection ‘up front’ on a site ‘checking’ the input for desirability before it gets to any specific component. After that it would be up to the specific component perform its checking. Do you really want to add the ‘words to be filtered’ to your blog component and your forum component, and to your article commenting component? You may do, but I/we certainly have better things to do with our time.
A tool such as Akeeba Admin Tools Pro, provides such a solution and the Web Filtering option (which includes word filtering, IP blocking, Bad Behavior) is (in our opinion) the way to go. Most sites implement some form of SEO and SH404SEF is the most common, and it comes with Project Honey Pot integration.
Some of these tools costs money (in our opinion considered reasonable), but one has to ask one self ‘How much is our site reputation worth?’. That is not something we can answer for you.
We therefore are reluctant to ‘re-invent the wheel’ in our components beyond what is considered reasonable. The Issue Tracker component (which can best fit into the comment/forum data entry consideration), all versions implement, IP blocking, White lists, Black Lists, Word filtering end ReCaptcha. As a result of a specific request we have implemented Aksimet checking as well in Release 1.2.1, even though we do not make use of it ourselves.
If your site uses a good ‘passive solution’ up front then these (apart from the ReCaptcha) can be left unused, but of course not everyone agrees so these options will remain ‘just in case’.