Sonos, Tile, Basecamp and PopSockets appeared in Boulder, Colorado to testify before Congress today.

The four tech companies sell a diverse range of products, like speakers, tracking devices, software and phone accessories. But they all alleged that Big Tech firms had 'bullied' them into abiding by their rules.

"Big Tech is bent on expanding until it does absolutely everything, Basecamp CTO David Heinemeier Hansson said, quipping, "Help us Congress, you're our only hope."

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Google, Amazon, Facebook and Apple were the subjects of scathing criticism by smaller tech companies during a Congressional hearing on Friday.

An assortment of tech firms that sell everything from speakers to phone accessories accused the tech giants of bullying business tactics.

"There's such a dominant power that exists with these companies that when Google or Apple asks for something ... you have no choice but to provide that to those companies," Patrick Spence, the CEO of wireless speaker company Sonos, told lawmakers.

Sonos, Tile, Basecamp, and PopSockets all appeared Friday at a hearing by the House Judiciary Subcommittee on Antitrust, Commercial and Administrative Law. Speaking at so-called "field hearing" that took place at the University of Colorado Law School in Boulder, Colo., the executives called for Congress to implement tougher regulation of Big Tech.

The executives told similar stories about how the larger tech companies had used their dominance in one market to cripple competition in its emerging products and tilt the field in their favors for its other product lines.

"At some point, all companies will be competing against Big Tech simply because Big Tech is bent on expanding until it does absolutely everything," Basecamp CTO David Heinemeier Hansson added, and quipped, "Help us Congress, you're our only hope."

Got a similar story about Apple, Google or Amazon's practices? Feel free to contact this reporter via Twitter @bani_sapra or contact by email at bsapra@businessinsider.com. You can also contact me via encrypted email at bsapra@protonmail.com or Telegram @bani_sapra.

Here's how Apple, Google and Amazon use their size to bully smaller tech firms, according to the executives who testified: