However, this campaign is misconceived to the very point of daftness. Companies have to comply with the relevant tax regime: they really have no choice. Companies have to pay all tax which is lawfully due. Lawfully due tax cannot be avoided, regardless of ingenuity or greed. Accordingly, if certain companies are not paying enough tax, then the only solution is to improve tax legislation and properly resource its implementation by HMRC.
I can see the logic here but that doesn't mean there's no logic to the UKUncut campaign. This illustrates a typical catch 22 for protesters: any campaign which captures the public imagination enough to be successful will have simplistic aims and will be directed at an easy target several rhetorical meters away from the real cause of the problem. Campaigns which perfectly identify the best solution to a problem, taking into account complex legal or tax issues, as well as a change in regime, will be accurate but largely unnoticed.
This doesn't mean that no protests can be effective, however. The point is to draw attention to a wider, ongoing problem and create enough pressure that something has to give. Any legal changes which result from this will be more subtle and better targeted than the protests themselves. It may be a little unfair on shareholders and customers of a few high street chains in the meantime, but the government set the standard for unfairness in this battle when it started cutting budgets like an axe-wielding maniac.
Look at any revolution in history and you'll find that the most symbolically effective elements were also the least logical. When the creators of the problem are no longer in power, when the ruling party clearly doesn't give a crap about the consequences of its cuts, when those who could make the changes are shrugging their bespoke-suited shoulders or condescendingly explaining the realities of high finance to a population facing job loss, pension losses, pay freezes, benefit cuts, inflation, increased VAT, repossession of their homes...
In the face of all that illogical, "daft" unfairness, you might as well storm the bloody Bastille, if only to get some exercise.