Both Peter Woit and Lee Smolin, in their respective books critical of string theory, drew attention to the level of personal abuse they had suffered at the hands of string theorists.
The poster child for abuse is usually identified as Lubos Motl (incendiary blog here). An example of his approach can be seen if you try to navigate to his blog from Peter Woit's blog "Not Even Wrong". You get the following page thrown at you (here).
See also Sabine Hossenfelder's blog "Backreaction" here, as updated today, from someone who's just had enough.
And then there were the recent personal attacks on Peter Woit's own blog, here. Scroll down to the anonymous string theorist "Lucy in the sky" here for something even more venomous.
I was then even more surprised to hear the leading string theorist Leonard Susskind, whose book on "Black Hole wars" I just reviewed, saying some extraordinarily offensive things about both Peter Woit and Lee Smolin on an American talk radio programme (about 3 or 4 minutes in, here). Woit is the 'computer programmer and bitter failed physicist' and Smolin the dilettante whose multiple theories vanish - glubb - glubb - glubb - even faster than he can make them up.
As far as research credentials go, probably the kind of mind which can encompass and critique a whole research programme is rather different than that required to push the edge of the very state-of-the-art. However the best critique is to find something better. As string theory has seemed exhausted to some observers, while nothing better has exploded on the scene, everything seems set for a long war of attrition.
I have two observations: (a) it will all get resolved on a time scale of decades but people will never be that patient; (b) it all gives fundamental physics a terrible reputation for the next generation wondering if they should get into it.