Any thread involving prisoners' rights tends to polarise fairly quickly into the two camps - those who believe that a criminal conviction forfeits the rights extended to the rest of society, and those who see the situation as somewhat more complex.
My belief has always been the same - the punishment involved in imprisonment is the removal of liberty. That is the punishment, it does not include add-ons such as loss of dignity and basic human rights.
That said - it does appear that the desire to ensure that rights are adhered to has resulted in both wholesale abuse of the systems, and a perhaps over-zealous willingness to be seen to be politically correct.
As other posters have opined, the obviously frivolous and false claims should be dismissed at the earliest opportunity, and the genuine and serious cases should be dealt with appropriately and proportionately.
We must bear in mind that a prison system does concentrate the minds of inmates inwards - they have little to occupy their time, and their situation makes their own sense of self expand to fill their thinking. This leads to a hyper-sensitivity towards perceived unfair personal treatment and a zealous desire to pursue a positive result.
That is an instant recipe for claims from the trivial to the serious, and rigorous checking and monitoring procedures should be in place to ensure that meaningless attempts to make waves and attract attention are not being entertained, and that genuine abuses are being assessed and addressed apropropriatly.