Actually, a lot of this 'US supports the Irish Republican Army' paranoia came from a simple misunderstanding between the cultures of the US and the UK.
'IRA contributions' in the US refers to Individual Retirement Accounts! These are plans which allow people to make contributions each year if they meet the contribution requirements. If aged 50 or older, they can contribute even more to their IRAs.
When MacDonalds employees arranged a corporate IRA contribution system, the false rumour spread around the UK that 'MacDonalds supports the Irish Republican Army'....