For my part, I've a bit of a divided opinion on the views cast towards my IG-faction of choice. (the fed.)
First off, the general banter is borderline acceptable. Mostly when crap gets flung at the Fed, (or used to back when I RP'ed actively) my toons took offense only when complaints were accusations not based around any kind of evidence or supportable claims, usually the most far-fetched accusations of the "lol yo su ebil" kind with no weight behind them. These were usually swiftly smacked down or written of as the unsupported ramblings of moronic anti-feds who clearly had no plan in mind beyond smack and banter for the sake of it.
On the other hand random claims or remarks meant to put the fed down as opposed to another faction or whatever usually did not see to much involvement - mostly these were more "innocent" opinions voiced by toons who simply did not live in or care for, the fed. Mostly considered harmless as they were 'only' the opinions of different toons, and only argued if it tended to get out of line or slip into unsupported ramblings, as above.
The only factor that actually bothered me, IC and OOC, was cases like the defections of Thulkalat, Nyxx, Nikita, Tyr Cloudstone and other former Pro-Feds who had suddenly "seen the light". This is where I feel the offense - long-standing supporters that spent time and effort assisting their chosen faction find out - all of a sudden - that they want to do something else. OOC inspired, no doubt. "Tired of this, find something else to do." The universal exit? Defect to the Angels, Guristas, Caldari or whoever and lay down the flames for the Fed while your at it.
I'm sick and tired of seeing toons leave faction X for Y and doing a complete 180, accusing their former faction and companions of being fools, supporting a corrupt and worthless cause, being to dumb to leave while they can, etc. etc. etc. The problem is not that they wanted to do something else, or that they did do something else, the problem is all of a sudden the cause they had given their all for or atl found enough reason to actively support is below worthless, beneath them, weak and deserving to be destroyed. Usually for fanciful and highly unlikely reasons.
As for CONCORD, most IC complaints I've seen directed at them comes form the pirates and pirate faction servants, and their agenda is as obvious as the sun. Other factions occasionally yell at CONCORD as well, like the Ushra'Khan, usually claiming some bias towards the Amarr Empire or whatever. That source of complaints are normally backed with some good arguments, even if the nature of the game means those arguments are flawed, flaws that people can use as counter-arguments.
On another topic I highly doubt that the criminal underworld thrives in the Fed due to very lax police laws as a general factor - there have been hints in many works of PF that the Fed as a general rule takes law-enforcement and combating the criminal element and black-market smuggling of anything from the latest drugs to pleasure slaves and other human-trafficking events very seriously. Their problem however is the very nature of the Fed - hundred of not thousands of member factions of varying size and methods. Some will be more capable in the local law-enforcement than others, some will be more corruptible than others, and more competent/incompetent. Another factor is that the Fed's primary "pirate enemy" is their nemesis in the Serpentis corp, and they have decades of practice in smuggling goods into the Fed any way they can, among them an extensive network of hidden dead-space gates and such. There is also the scope and scale of the nation and it's war on criminals to consider - many worlds may well be festering sores on the Fed's name due to rampant criminal activity and be quite unpleasant places, while others can be the complete opposite - cities, regions on planets or even entire planets that are effectively free of any major, organized crime. There is little if any PF that explains any of this, in fact, PF that details the levels of criminal influence any any of the empires don't exist IIRC. I'd love to read up on how bad/widespread/influential criminals or undesirables are in any nation, how entrenched are the Angels in Heimatar, for instance? I'd love to know.
However, final point is nothing indicates that the Fed is somehow more lenient towards crime or lawbreakers based on governmental design - it's not 'easier' to be a criminal in the Fed than anywhere else based on how the nation polices itself or organizes, but the citizenry does seem to be a greater mix of opinions and attitudes randing all the way from "I Don't care to have my Serpentis bro's arrested, and this dope is the **** yo" to activists calling for more police-state like conditions to combat what they see as a major issue. Federals do love their activist causes, after all.