What do you all think? Is it legal? Is it the right thing to do? Do you think I'll have any negative fall out from my user base?
Welcome to WebmasterWorld (if this is your first post).
I think some people here would say yes, some would say no, and some would say consult a lawyer. I think that you'll need to make this decision for yourself.
Personally I would not do it - but I know others who would. In some circumstances I'd even do the opposite to what you suggest - i.e. I'd warn the competitor about it. Just speaking to your competitor would open up the potential for more communication, the sharing of information in the future, or at least the potential to find out more about them.
Only a lawyer can tell you for sure if its legal or not - but if its very similiar to their trademark or contains their trademark then the odds (in my opinion) would be in their favour, not yours. Personally I'd say if in doubt, don't do it.
I decided not to do it because I think it will end up hurting my own credibility, especially if it gets out to my user base that I am the one who did it.
One thing I've learned on the net is that unethical actions are difficult to erase and sometimes they could do long term damage that isn't apparent right away.