Another thing about BBS's was that this was the age before Amazon web services and the endless fields of Google zombies, with their brains hijacked to run massively parallel computing. If you wanted to BBS, you likely ran it out of your closed with a computer hooked up to your phone line... Which meant that there could often only be one person actually on the BBS at once, since they were dialing in and taking up the phone line. So they'd post their stuff, or take their (game) turn, or whatever, and then get off for the next person.
Those that were particularly flush, or hijacking resources from someone else (why your BBS might only be running after business hours), would have multiple lines and a PBX box, and either multiple acoustic couplers, or just several banks of modems so the host machine could have some number of distinct connections at once.
That's part of why LAN parties were a thing, where you would all pack up your computers, and meet up somewhere to plug everything in together to make a local network out of them.
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As for explosives, you can make a pretty good bomb out of fertilizer (all those nitrogen atoms want to be free) plus a wetting agent (usually diesel fuel), though there tends to be some monitoring of (bulk) fertilizer purchases; at least, in the US after the Oklahoma City Bombing (1995). I'd assume, with the PIRA running around the UK, they were doing it even earlier.
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The troubles (in Ireland) are finally trying to wind down, but the PIRA should still have some stockpiles of small arms and stuff around somewhere.
